Graphics Performance

With the Core i7-7660U, we finally get a chance to look at the Intel Iris Plus Graphics 640 in a notebook. On a typical U series Intel Core processor, there are 24 execution units (EUs) available, but the Iris Plus doubles that to 48. Despite having the same TDP, having twice as many EUs running should still be a big boost to performance, as even if they need to throttle, there are twice as many, so they can run slow and wide and still fit in the TDP. The base frequency for the graphics is 300 MHz, with a 1.1 GHz boost frequency.

The addition of 64 MB of eDRAM is also a large benefit to graphics, which needs a lot more memory bandwidth than the CPU, and having this extra eDRAM as a cache for the GPU is a big benefit to the Iris Plus graphics.

In the graphs below, make note that the Dell XPS 15 has a GTX 960M graphics card, which should win pretty handily, but the Surface Book has a smaller GT 940M with 2 GB of GDDR5, so it will be interesting to see the performance difference between the integrated Iris Plus Graphics 640, and a discrete entry-level GPU.

3DMark

Futuremark 3DMark Fire Strike

Futuremark 3DMark Sky Diver

Futuremark 3DMark Cloud Gate

Futuremark 3DMark Ice Storm Unlimited

Futuremark 3DMark Ice Storm Unlimited - Graphics

Futuremark 3DMark Ice Storm Unlimited - Physics

Futuremark’s 3DMark continues to be developed, and new tests have been added for higher end systems, but for our purposes on this review, the normal results will do just fine. Each of the tests move from quality to performance, with Fire Strike being the most demanding, and Ice Storm Unlimited being a smartphone or tablet test. The GT 940M in the Surface Book still manages to hold an edge on the more graphically demanding tests, but is then surpassed as the workload gets easier, and the test becomes more CPU bound. Compared to the non-Iris Ultrabooks though, the i7-7660U delivers a lot more performance.

GFXBench

GFXBench 3.0 Manhattan Offscreen 1080p

GFXBench 3.0 T-Rex Offscreen 1080p

Another synthetic, Kishonti’s GFXBench also continues to evolve, with new tests being added to provide more stressful tests than the older T-Rex and Manhattan ones. Since we don’t have any comparison data, for now we’ll stick with the older tests while we fill out the data gaps. The Intel Iris graphics pull out a hefty lead here.

Dota 2

Valve’s Dota 2 online area game continues to be our go-to game for testing systems with lower end graphics, since it has a low barrier of entry, and is quite playable at low settings even on a system with integrated graphics.

Dota 2 Reborn - Value

Dota 2 Reborn - Mainstream

Dota 2 Reborn - Enthusiast

Here the Iris Plus Graphics do not bring the kind of improvement that would have been hoped for. At lower settings, they are very capable, and the extra CPU speed from the i7-7660U helps break the CPU bound barrier of the other systems, but once the graphics are turned up, the U series chip runs into the thermal barrier of only having a 15-Watt TDP. Compared to the Microsoft Surface Book, with it’s discrete GT 940M GPU, there’s really no contest, since that GPU alone would have 20-30 Watts of TDP available to it. The Iris does allow a lot more graphics potential, but for longer duration requirements, it may not offer much of an upgrade.

Graphics Conclusion

It’s great to finally be able to test a system with a U Series CPU and Iris graphics, and the results are quite impressive. It’s not quite up to par with even a low-end discrete GPU, but compared to the other integrated GPUs available in the other Ultrabooks, the Iris really brings the performance up a step. For light gaming, it should work well, but the extra eDRAM can help out on practically any task. The extra EUs available would also be of benefit to any productivity app that can leverage the GPU for some of its compute.

Storage Performance

PCIe SSDs have been the name of the game for the last couple of generations of Ultrabooks, but they’ve generally been shipping in the M.2 form factor. Microsoft has gone a different route with the new Surface Pro, by moving to a much smaller BGA SSD in the Samsung PM971.

The benefits of going this route are mostly packaging. The BGA SSD is significantly smaller than any M.2 SSD, especially the 2280 versions that are the most common. The drive is also most likely more energy efficient than the fastest SSDs available today, which should help with battery life.

There is likely only one downside to the PM971 BGA SSD, and that is performance. While still much faster than a SATA SSD, the PM971 is limited to a PCIe 3.0 x2 link, which is going to impact the maximum read and write speeds.

As you can see in the CrystalDiskMark test, the maximum read speed is well under something like a Samsung SM961. This may seem like bad news, but in fact the PM971 actually outperforms the same size PM951 drive which was easily the most popular SSD found in Ultrabooks until recently. The PM971 is 48 layer TLC NAND, with reasonable write speeds, and other than the lowered maximums created by the PCIe link being x2 instead of x4, the performance is quite good.

When you look at a device like the Surface Pro, where space is at a premium, these are the kinds of compromises that make sense when you consider that they’ve increased the battery capacity by 15%, and despite going with a compact SSD, they’ve still increased performance over the outgoing model assuming it had a PM951, which it seemed most did.

System Performance: Kaby Lake with Iris Plus Graphics Display Analysis
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  • mkozakewich - Saturday, June 17, 2017 - link

    I swear I say this every time, but it bears repeating: One of the original ideas about ultrabooks was that we could throttle them while mobile, but then run them at full power by using some kind of cooling dock. Same thing here: If you had (or made?) something that cools off the chassis, it'll reach higher performance levels. Using it outside on a cold and windy day will give you more frames per second. Stuff like that.
  • tipoo - Monday, June 19, 2017 - link

    Yup, very interested about the fanless 15W i5 and how well that can keep up. In theory it would act pretty Core M-ey.
  • anactoraaron - Thursday, June 15, 2017 - link

    I remember owning a pro 4 and being disappointed learning that the review samples used a faster ssd. All retail units had much slower ssds and a ridiculous amount of light bleed on the displays. I had one at launch (and returned a few to try and get less light bleed and perhaps the faster ssd used by the review units) but the first time I got a blue screen negating over an hour of work it had to go. It was a great concept, as I ultimately went with the Vaio Z Canvas (during the fire sale). The Vaio has been by far the better option, with plenty of ports and power (not to mention it also has a better display) to its advantage over the surface pro.
  • SaolDan - Thursday, June 15, 2017 - link

    I actually owned a sp4 i5 with the toshiba ssd and it had faster write. about 1GBps write speed. But tbe screen developed a small preasure point and i got it replaced. I got a samsung ssd on the replacement. not as fast.
  • samnish - Thursday, June 15, 2017 - link

    As an owner of Surface Pro 2 and 4, I must say, I went from loving the idea to hating the series. To list a few issues:
    - Normal sleep mode never works. Either it wakes up to a black screen, or it used up all the battery while sleeping. It is pretty much required to disable sleep and use hibernation instead.
    - The Wacom pen on SP2 worked well. The one on the SP4 is a huge step downwards. If you want to draw a straight line, you need to draw it by the edge of the screen, because when you draw in the middle of the screen it'd give you a squigly line. Happaned even after exchanging for another one at MS store.
    - On the SP4, I encountered a bug where a process "Microsoft IME" would hog up 100% of the CPU. If memory serves, it was introduced by the Anniversary Update. After a lengthy thread on Microsoft forum with many other victims, MS did fix it. But it took them 3 months.
    - When charging, if the SP4 is grounded slightly different than myself, the touchpad would have an jittery response. I have to touch the chassis of the SP4 with my other hand to make the touchpad work normally. Happaned even after exchanging for another one at MS store.

    This is enough examples. The Surface Pro series was Microsoft's poster child, yet they couldn't even get all the basic laptop features working stably for 4 generations. With laptops from other manufacturers, one can defend MS by saying "they have many different hardware to support, drivers take time to mature". Sure. What about the Surface Pro series? You can't really defend them with the same points - all the hardware is chosen and supported by Microsoft themselves. By Surface Pro 4, they really shouldn't still be struggling with delivering firmware that don't break your hardware and a sleep mode that works. I hope the new Surface Pro fares better this time on these departments, but I don't have high hopes for them. Microsoft has a much stronger showing for innovation in recent years, yet the hardware that they deliver are full of small glitches, and the stability of their consumer operating system has been such a mess.
  • mkozakewich - Saturday, June 17, 2017 - link

    I had a lot of problems with the little things. When I close my cover, the touchpad starts activating the screen, causing it to wake from sleep or start dragging icons around. I'm actually having a more consistent time with my $400 Chuwi. It feels weirdly magical to be able to close it without worrying about it waking up again.
  • tipoo - Thursday, June 15, 2017 - link

    Pretty curious about that 15W fanless middle tier. I'm assuming it would act pretty Core M-ey, but I wonder if it would do worse than silicon selected for the lower TDP, or if the chips are pretty much the same with different TDP-Downs.
  • id4andrei - Thursday, June 15, 2017 - link

    The Core M SP4 had great cooling. As long as the fanless i5 throttles at about the same threshold as ultrabooks with fans it would be a success.
  • KPOM - Sunday, June 18, 2017 - link

    The 15w cpus can downvolt to 7W. I wounded if that is what Microsoft is doing with the i5.
  • tipoo - Monday, June 19, 2017 - link

    Yeah that's what I meant about the TDP-Down, in theory a 15W chip with a tdp-down to 7W and a 5W chip with a TDP-up to 7W would act the same as the silicon is the same.

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