Review: Intel’s Broadwell mini PC is a next-generation Ultrabook in a box

Intel’s “Next Unit of Computing” (NUC) was one of our favorite gadgets last year. Desktop computers aren’t exactly the most exciting things in the world of technology right now, but there’s something to be said for a fast, versatile, upgradeable desktop that can squeeze underneath a monitor stand next to a stack of phones.

Intel unveiled a new NUC lineup at CES last month alongside the second wave of its oft-delayed Broadwell processors. The desktops look similar from the outside, but on the inside everything from the CPU and GPU to the Wi-Fi card to the storage interface has changed.

This review will serve three purposes then. We’ll evaluate the Broadwell NUC as a standalone piece of technology. We’ll look at Broadwell U and the kind of performance improvements and power usage reductions it delivers relative to equivalent Haswell U processors. And we’ll take a broader look at the kinds of technology you can expect in your next laptop.

What it costs and who it’s for

This is the third generation of NUC. Each generation has been tweaked and improved, but they’ve all been the same kind of box. The ones Intel sells directly aren’t complete computers but “barebone kits.” When you buy it, you get the enclosure, the power adapter, the motherboard, and the CPU (this is an Ultrabook CPU, so it’s soldered to the motherboard and the chipset is integrated onto the package).

You need to bring your own memory and storage, though unlike previous NUCs Intel has seen fit to include an Intel 7265 802.11ac and Bluetooth 4.0 combo adapter. You’ll need to bring up to two sticks of DDR3 RAM—the NUC supports up to 16GB of memory and for best performance you should add sticks in matched pairs—and a solid-state drive that will fit in an M.2 slot. We’ll talk more about M.2 in a bit, but first let’s look at the cost of a finished NUC system.

Intel won’t commit to a firm MSRP for this year’s NUC, just that it will be “on parity with comparable [Haswell] SKUs.” The company says that the “street price” for Core i5 Broadwell NUCs will probably be around $430, $40 more than what the Haswell NUC cost when we reviewed it a year ago. A less expensive Core i3 version and a more expensive Core i7 version will follow in the coming months, alongside models that will hold 2.5-inch hard drives and business-friendly variants. The final cost is entirely up to you, which is kind of nice if you don’t want to deal with OEM markups on RAM and SSDs.

The unfortunate thing is that there aren’t many M.2 SSDs for regular end users to buy right now—you have nowhere near the same number of options as you do with 2.5-inch drives or even older mSATA cards. Faster PCI Express-compatible M.2 SSDs are even rarer and roughly twice as expensive. Expect this to change as the big players in the SSD space begin developing and shipping more M.2 drives, but that doesn’t really help you if you’re trying to piece together a NUC today.

Consider a middle-of-the-road NUC with 8GB of RAM and a 256GB SATA SSD: what you get for the money actually isn’t unreasonable. Other desktops have lower starting prices but make other sacrifices to get there—usually less RAM and a spinning HDD. The NUC’s three-year warranty is awfully appealing compared to the one-year standard offered by the majority of OEMs. Other companies will also take a few months to upgrade systems from Haswell to Broadwell.

The mini PC market is more crowded than it was a year ago, and new players like Dell and especially HP have cruised in with small desktops that offer less power but dip well below $400. Ask yourself how much computer you need: if you want a small PC that performs like a premium Ultrabook, the NUC is for you. If you’re replacing a lightly used hoary old desktop from five years ago for a family member, the $320 HP Pavilion Mini is an awfully tempting option. The $179 Stream Mini desktop is intriguing for certain use cases, too, but with 2GB of RAM and 32GB of storage it would make for a poor general-use desktop. It would be better for basic HTPC or Web kiosk usage.

In a small way, the NUC scratches an itch for a certain type of lapsed desktop builder, the type that used to build more towers but has since (by preference or necessity) moved to more tightly integrated systems. No, it’s not really the same, but users still get to compare, price out, and install some components and set up the software. And you don’t have some giant chunky ATX tower sitting under your desk afterward.

NUC version 3.0

The NUC and its new, smaller power brick.

Andrew Cunningham

The NUC and its new, smaller power brick. Andrew Cunningham

A NUC waiting for components. Standoffs are available for 42mm, 60mm, and 80mm-long M.2 SSDs.

Andrew Cunningham

A NUC waiting for components. Standoffs are available for 42mm, 60mm, and 80mm-long M.2 SSDs. Andrew Cunningham

Populated with two sticks of DDR3 RAM and a 256GB, 80MM SSD.

Andrew Cunningham

Populated with two sticks of DDR3 RAM and a 256GB, 80MM SSD. Andrew Cunningham

A NUC waiting for components. Standoffs are available for 42mm, 60mm, and 80mm-long M.2 SSDs. Andrew Cunningham

Populated with two sticks of DDR3 RAM and a 256GB, 80MM SSD. Andrew Cunningham

The Broadwell NUC (top) has the same port selection as the Haswell model (middle), just moved around a little bit. The Ivy Bridge model’s port selection is inferior but it’s still the only NUC with Thunderbolt.

Andrew Cunningham

Left to right: Broadwell, Haswell, and Ivy Bridge NUCs.

Andrew Cunningham

This particular version of the Broadwell NUC is just a bit smaller than the Haswell version in every dimension, though the difference is so small that it’s hard to tell even when they’re sitting right next to each other. The move from the first-generation Ivy Bridge NUC to the Haswell version had a much larger impact on the size of the chassis and the port layout.

The Broadwell NUC has the same basic complement of ports as the outgoing model: two USB 3.0 ports on the front and two on the back; a gigabit Ethernet jack; mini DisplayPort and mini HDMI; a headphone jack; and an IR receiver. It’d be nice to see that mini HDMI port get replaced with the sturdier and much more common full-size HDMI port, but it’s a good layout for a desktop of this size.

One of the front USB ports has changed—the yellow one is a “charging port,” and it can provide between 500 and 1,500 mA of power, rather than USB 3.0’s standard 900 mA. It still works like a regular USB port for connected flash drives and other peripherals, but it can provide more power to phones and tablets that are plugged into it. The port will continue to charge devices even if the rest of the system is powered down.

Another neat addition is the presence of removable lids, which opens up expansion possibilities beyond USB adapters and dongles. Lids can be switched purely for aesthetic reasons, but they’ll be able to hook into the USB 2.0 bus to add extra stuff—there’s one USB header on the motherboard, and one separate NFC header for lids that want to add that particular feature. Intel has already shown off an NFC lid and a prototype TV tuner lid from Hauppauge. Lids that turn the top of the NUC into a wireless charging pad have been rumored. And a note included with our review NUC mentioned VGA ports, serial ports, and extra USB ports.

The usefulness of this feature is going to depend almost entirely on what companies show up with lids and the types of things those lids can do. Even the limited selection of lids we’ve seen and heard about are enough to pique our interest. Keep an eye on it.

The NUC’s lid can be removed and replaced for functional and aesthetic reasons. To the left, an NFC lid. To the right, a TV tuner lid.

Credit: Andrew Cunningham

To open up the NUC, flip it upside down and loosen the four captive Phillips head screws. Pull the bottom off and all of the user-accessible stuff is there on the bottom of the motherboard. A single, smaller Phillips head screw will need to be removed so you can put the M.2 SSD in its slot. Put the screw back in to secure the drive, put the bottom back on the NUC, and you’re ready to install your software.

If you (very carefully) disconnect the antennas from the Wi-Fi card and unscrew the four additional Phillips head screws in the corners, you can slide the NUC’s motherboard out of its box. There aren’t a whole lot of reasons to do this, but it does give you access to the heatsink and fan assembly that sits on top of the CPU.

There’s also a standard-sized SATA III port on the bottom of the board. There’s no space in this case for a standard 2.5-inch laptop hard drive, but the alternate, taller NUCs and custom enclosures using this board will be able to fit one in alongside the M.2 drive.

Finally, let’s turn our attention to the power adapter. The end that plugs into the NUC is exactly the same as the one used in the last two generations and the 65W adapter has the same power output, but it’s considerably more svelte. The plug part slides off and can be replaced with alternate international plugs or longer cords, much like some laptop power supplies. The old power brick is generic to the extreme, but the new one is actually pretty nice. Every year Intel seems to tweak the NUC to make it more like a mainstream consumer device and less like a weird side-project for tinkerers.

Power consumption and fan noise

One of the draws of these tightly integrated mini PCs is that they use the same guts as Ultrabooks—all the stuff Intel is doing to extend your laptop’s battery life should make the NUC draw less power at the wall. We used a Kill-A-Watt meter to compare the Broadwell NUC to the Haswell and Ivy Bridge models to get an idea of where Intel is saving the power it says it’s saving.

All of the Broadwell NUC’s power consumption numbers are broadly comparable to the Haswell versions, if not just a bit higher. Remember that we’re evaluating whole systems here, so the small increases we’re seeing in some of these tests may be attributable to components other than the CPU—the Wi-Fi card and SSD aren’t the same in all systems since the Broadwell NUC uses different interfaces. In any case, they’re mostly in the same ballpark.

Because the active power consumption numbers are so similar, Broadwell’s purported battery life gains are probably coming from power savings when switching between these active and idle states; that’s where many of Haswell’s battery life improvements came from.

The single system fan in the Broadwell NUC is similar to the one in the Haswell NUC—it’s perhaps a little quieter, but at idle in a quiet room it’s still possible to hear the gentle whirring if you try. The higher-pitched whirr the fan makes when the system is under load is more audible, but it’s nothing like the jet-engine sounds we’ve heard from mini PCs like Gigabyte’s Brix Pro.

The next phase of SSDs and understanding the M.2 connector

Most solid-state drives released within the last year or so have been too fast for the bus they’re connected to. The 6Gbps SATA III spec was finalized in the days when rotational hard drives still ruled and SSDs were rare, ludicrously expensive, and relatively unreliable.

Things change with Broadwell and its accompanying chipset, which will let you hook SSDs directly into the PCI Express bus. The connector used to facilitate this change is called M.2 (previously NGFF, for “Next-Generation Form Factor”), a type of connector that is physically smaller and more versatile than the mSATA and mini PCIe connectors it’s replacing. Neither PCIe-connected storage (hi Apple) nor the M.2 connector itself are new, but beginning with Broadwell systems each of those two things will become much more common.

Let’s start with the physical connector and the things that connect to it. There’s a lot to unpack, starting with the fact that there’s no such thing as “an M.2 connector” or “an M.2 card.”

Four M.2 cards, from left to right: An A- and E-keyed Wi-Fi card, two B- and M-keyed SSDs, and an M-keyed SSD.

Credit: Andrew Cunningham

Above are four M.2 cards. The one on the left is a combo Wi-Fi and Bluetooth card. The next one to the right is a Sandisk SSD that uses the SATA bus. The next one is an Intel SSD that also uses SATA. The one on the right is a Samsung SSD that can use up to four PCI Express lanes.

Pay attention to two things as you compare and contrast these cards. First, the physical connector on each card is different; each card has different cutouts in the bottom and exposes different pins. Second, the cards are of different lengths and widths. All of this is accounted for in the M.2 spec (PDF).

The different connectors signify different M.2 “module keys.” Each key exposes a different set of interfaces to each card—M.2 can connect directly to the PCI Express bus, but different pins can be used to connect to the USB 2.0 and 3.0 buses, SATA III, DisplayPort, and a variety of other less-prevalent storage buses. Cards with one notch at the bottom are keyed for one specific kind of connector. Cards with two notches can be used in two different kinds of connectors.

Two M.2 slots on the motherboard of the HP Stream Mini. The left one is E-keyed and used for the Wi-Fi card. The right one is B-keyed and used for the SSD.

Credit: Andrew Cunningham

Above is a picture of two M.2 slots on the motherboard of an HP Stream Mini (review to come). The slot on the left uses module key E, and the one on the right uses module key B. The Wi-Fi card is keyed for slots A and E, so it fits in the left slot with no problems. The Intel SSD is keyed for slots B and M, so it fits in the right slot. The Samsung SSD is keyed for slot M, so it won’t fit in either of the Stream’s slots.

The table above lays out the keys in common use today—there are others, mostly placeholders to be called into service as newer buses and interfaces are introduced.

Note the four- or five-digit numbers paired with each slot. These are actually codes to refer to the physical dimensions of each card; the first two digits specify the width in millimeters and the second two or three digits specify the length. Our Wi-Fi module is 16mm wide and 30mm long, or 1630. Two of our SSDs are 22mm wide and 80mm long, or 2280. The other SSD is 22mm wide and 42mm long, or 2242. All motherboard slots are 22mm in width, even the ones attached to 30mm-wide cards.

All current keys can give cards access to two PCI Express lanes, but otherwise interface compatibility is all over the place—so far, it’s been pretty easy to guess what kind of peripheral you’re dealing with based on the key it uses. Wi-Fi and WWAN cards tend to use keys A and/or E, since they only need the PCI Express or USB 2.0 buses and only need 30mm in length to fit all their key components. SATA SSDs and SSDs that use two PCI Express lanes tend to use keys B and M to maximize compatibility, since both connectors can deliver both SATA III and two PCIe lanes. The very fastest SSDs tend to be M-keyed since it’s the only one that delivers four PCIe lanes.

This is a lot to digest, but it’s most of what you need to know to understand M.2. There are some other stipulations around the physical thickness of the cards that you can read about in the documentation, but they aren’t as important to our discussion today.

The key system isn’t always foolproof—our A- and E-keyed Wi-Fi module will physically fit into the B-keyed SSD slot even though the computer won’t recognize it there. M.2 is certainly more confusing than the mPCIe and mSATA specs, but in the end it’s more flexible. Components can access many different buses through one small internal connector, and you’ve got a lot of different physical card sizes to play with instead of being tied to either a “full-height” or “half-height” card.

The worst thing about M.2 right now is a general scarcity of components, but that will change as the connector goes mainstream and mPCIe and mSATA begin to fade. Broadwell is a big step forward in that transition.

M.2 in the NUC and storage performance

The consumer version of the Broadwell NUC uses a single M-keyed M.2 slot that supports cards up to 80mm in length—you can move the little metal standoff around on the board if you wants to use 42mm or 60mm drives instead, though. The commercial versions of the NUC will include a second M.2 connector usable either for Wi-Fi cards or other peripherals, but in the consumer version the Intel 7265 Wi-Fi card is soldered to the motherboard.

Intel sent us two M.2 SSDs with the NUC for testing: a 360GB Intel 530 that uses SATA III, and a 256GB Samsung XP941 drive that can use up to four PCI Express lanes. The M-keyed M.2 slot in the NUC supports four PCI Express 2.0 lanes, too, though this isn’t mandatory for system builders—we’re sure that some OEMs will ship B-keyed slots that only provide two PCIe lanes.

You’ll never have to worry about changing any settings if you swap a PCIe drive for a SATA one or vice-versa. Of the four PCI Express 2.0 lanes routed to that M.2 slot, Intel tells us that one will automatically change over to the SATA III bus if the system detects a SATA SSD. This is thanks to something Intel calls “Flexible I/O.” OEMs can switch a total of two lanes over to SATA operation, which is handy for those niche SSDs that support RAID 0 by including two separate SSD controllers and sets of NAND chips on a single drive (Acer seems to ship laptops that use this configuration the most often).

On systems that use Intel’s Smart Response Technology SSD caching feature, the SSD is also limited to two PCI Express 2.0 lanes. Intel tells us that future chipsets will support using four PCI Express 2.0 lanes with the Intel SRT feature, and they’ll speed things up further by adding PCI Express 3.0 support to the chipset itself. Intel desktops that support PCI Express 3.0 can do so because those lanes are integrated into the CPU, but so far the chipsets haven’t moved beyond version 2.0.

We ran a few tests just to get a feeling for how PCI Express drives paired with Broadwell would compare to SATA versions. An ideal test would use two drives from the same manufacturer with the same controller and capacity, since all of those things can have a pretty big impact on read and write performance, but for our purposes this will have to be good enough. We ran synthetic tests in Quickbench, measured boot times (from the time the power button is pressed until the Windows login screen showed up), and timed how quickly the system could copy a file from one folder to another folder on the same disk.

In all cases, PCI Express is an improvement. Windows 8 boot times are pretty quick no matter which interface you’re using, but QuickBench read scores improve by about 43 percent and write scores by around 59 percent. It only takes around a third of the time to copy a file from one place to another. Any SSD you can get will be pretty quick, and the high market price of PCIe SSDs will probably push most NUC buyers to start with a SATA drive anyway (this Samsung drive costs about $260, compared to just over $100 for a SATA M.2 drive of the same capacity). The performance improvements are definitely there, though.

CPU performance: Broadwell U is a mild bump

Broadwell is a “tick” on Intel’s roadmap, which means it takes its predecessor’s CPU architecture (Haswell) and moves it to a new manufacturing process (14nm). This arrangement helps to minimize the likelihood of manufacturing problems with new chips, though as we’ve seen with Broadwell’s delayed and protracted rollout, this strategy isn’t always 100 percent effective.

At any rate, “tick” years generally aren’t big ones for performance. A new manufacturing process gives Intel the ability to reduce power consumption, increase performance, or both, and the new NUC gives us a look at what kind of balance Broadwell strikes.

Here are the CPUs and GPUs we’re comparing in the charts below. All systems include 8GB of 1600MHz DDR3 RAM.

• The Broadwell NUC, which has a Core i5-5250U CPU and an Intel HD 6000 GPU.
• The Haswell NUC, which has a Core i5-4250U CPU and an Intel HD 5000 GPU.
• The Ivy Bridge NUC, which has a Core i3-3217U CPU and an Intel HD 4000 GPU.
• The 2015 Dell XPS 13, which has a Core i5-5200U CPU and an Intel HD 5500 GPU.
• The 2013 Dell XPS 13, which has a Core i3-4210U CPU and an Intel HD 4400 GPU.
• The Gigabyte Brix Pro, which has a quad-core Core i7-4770R and an Intel Iris Pro 5200 GPU.

Comparing the Broadwell i5-5250 to the Haswell i5-4250 is about as apples-to-apples as you can get. A higher clockspeed and architectural improvements help the new CPU beat its older counterpart by around 10 percent. Not an amazing leap forward after a year and a half wait, but not entirely unexpected given Broadwell’s “tick” status.

This may not be true for thin-and-light laptops with less room to dissipate heat, but despite having a “base” clock speed of 1.6GHz, the i5-5250 in the NUC can sustain a Turbo Boost clock speed around 2.4GHz indefinitely. We ran the Prime95 CPU torture test for more than 20 minutes, and the clock speed hung out somewhere between 2.37 and 2.45GHz for the entire time. Even the Haswell NUC would ramp down to about 2.0GHz under the same kind of sustained load.

It’s definitely something to consider if you’re comparing the i5 NUC to older i5 NUCs, or to versions without Turbo Boost—the base clock speeds don’t tell you everything you need to know.

GPU performance: A bigger jump, plus improved 4K support

Given the smallish CPU performance improvements, we were hoping for more drastic generation-to-generation performance gains on the graphics side. Intel has been prioritizing GPU improvements over CPU performance for the last few years, mostly because there was a gigantic performance chasm to close between its 2010-era GPUs and even the lowest-end dedicated graphics cards.

The i5-5250U includes the Intel HD 6000 integrated GPU, which is the third-fastest option in the lineup. The Iris Pro 6100 is the same GPU with a higher clockspeed and larger thermal envelope, and there’s an as-yet-unreleased Iris Pro 6200 GPU coming with future Broadwell chips that will add integrated eDRAM to boost memory bandwidth (Intel hasn’t announced it officially and we don’t have final specs for it, but it’s mentioned by name on this support page for Intel GPUs).

We’ve compared the HD 6000 to a bunch of different integrated GPUs here, but the ones to pay the most attention to are the HD 5000 (the equivalent Haswell GPU) and the HD 5500 (the next-lowest Broadwell GPU, and the one most PC OEMs will end up using in Ultrabooks).

Here, Broadwell is definitely a better performer than Haswell. In most of our benchmarks, the HD 6000 is between 20 and 30 percent faster than HD 5000. It often doubles the performance of Ivy Bridge’s HD 4000.

Still, it feels like the HD 6000 should really be able to go faster than it does. The HD 5500 is a little bit faster than Haswell’s HD 5000, too, which is strange because it’s got far fewer execution units (EUs). Doubling the number of EUs for the HD 6000 and increasing the clock speed doesn’t give you anywhere near double the HD 5500’s graphics performance. That was the case with Haswell as well—HD 5000 had double the EUs of HD 4400, but not twice the performance.

Our best guess is that the higher-end integrated GPUs need more memory bandwidth to perform to their fullest potential. The Iris Pro 5200 is the same GPU as the HD 5000, but it includes 128MB of eDRAM on the processor package. As a result, Iris Pro 5200 is drastically faster than every single one of the other integrated GPUs on our list. There are certain benchmarks—the GFXBench Manhattan test, the 3DMark Cloud Gate test—in which the HD 6000 and HD 5500 perform very similarly. The HD 5000 and HD 4400 share similar performance in the same benchmarks. That suggests a memory bandwidth problem that a faster GPU with more EUs just can’t overcome. Broadwell chips with integrated eDRAM won’t show up until later this year—that’s when we’ll really see what the new Broadwell GPU can do.

Technical quirks aside, how does the new NUC fare when it’s actually playing games? One of Intel’s taglines for this NUC is that it’s “a LAN party that fits in your pocket.” Leaving aside the question of whether anyone still has honest-to-goodness LAN parties in the year 2015, the tagline isn’t wrong. Some older and lighter titles—the first Bioshock, Portal 2, Minecraft—can be played smoothly in 1080p with all the settings turned up. In Portal, we could even enable some anti-aliasing. It’s a really excellent box if you’re trying to play through your back catalog.

Slightly more modern or taxing games like Bioshock Infinite give the HD 6000 more trouble; 1080p gameplay is a bit jerky even with all the settings turned down, but you can still play at 720p and medium quality settings. In Skyrim, 1080p gameplay at the Ultra settings level looks like a flipbook, but turn the settings down to low and things are surprisingly smooth (720p and Medium settings work pretty well too).

The HD 6000 doesn’t improve enough over the HD 5000 to make previously unplayable games playable (though luckily pretty much everything is playable on both of them). What it will get you is a couple of extra quality settings, or perhaps an extra step up in resolution. It’s the difference between a slightly choppy 25 frames-per-second and a smooth 30 frames-per-second. The NUC is emphatically not a 4K gaming box, but if we’re talking 720p or 1080p it’s surprisingly capable if you manage your expectations properly.

If you’re not a gamer, the NUC’s new GPU still has some nice improvements for you. Chief among them is 60Hz 4K support over the DisplayPort protocol—the Haswell NUC had a DisplayPort 1.2 connector, but the HD 5000’s refresh rate was limited to 30Hz when running at 4K. The HDMI port can drive a 4096×2304 display at 4K, too, but it’s limited to 24Hz. As with the Haswell NUC, the Broadwell version can support up to three displays at once if you use am HDMI monitor plus two DisplayPort monitors that are daisy-chained or connected to a capable DisplayPort splitter.

Conclusions

Three iterations in, Intel has figured out what it wants the NUC to be. It’s part hobbyist project, part low-end gaming PC, and part miniature workstation. It offers enough power for anyone who doesn’t need a quad-core CPU or a dedicated graphics card, and it would be a great drop-in replacement for a mini-tower desktop that’s been around for three-to-five years.

As an Ultrabook in a box, the NUCs also serve as showcases for new Intel CPU, GPU, and chipset features. The Broadwell NUC shows us what kind of performance we can expect from solid-state drives in the next year or so. It’s better-prepared for our seemingly inevitable 4K future. It manages to keep power consumption about even with Haswell while increasing performance. That said, if you already have a Haswell NUC, there’s not really enough new stuff here to merit buying the latest one.

This year, Intel is going to sell more NUCs by increasing the size of the lineup—we saw most of them when the new NUCs were announced. There’s a Core i7 model with an Iris 6100 GPU. There are models with space for an integrated 2.5-inch HDD (Haswell versions of these exist, though they weren’t introduced until later in the product cycle). There are models specifically for businesses that support vPro and include TPMs and have a cutout in the back for a serial port. Intel’s not trying to get you to upgrade your NUC, it’s trying to make the NUC workable for more people in more places.

Our main criticisms of the consumer NUC are the same as last year. Because you need to track down and buy some components yourself, it might not be the easiest thing to recommend to a regular PC buyer. Once you’ve paid for the box, the RAM, and the SSD, you’ve spent more than you would have on an entry-level desktop or mini PC even though the NUC will usually be the faster computer. We still like it for what it is, though—a surprisingly capable desktop that can fit pretty much anywhere.