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I just patched the Surface Book with the Meltdown and Spectre patches. Here’s how much it hurt.

- BY GORDON MAH UNG

As a performanc­e junkie, I’m less concerned about the security risks of the Spectre and Meltdown vulnerabil­ities (see page 115)—after all, there are no known exploits in use today—than I am about a performanc­e hit from the fixes.

And from what I’m seeing, my concerns are warranted.

My sole experience with a fully updated

platform so far is with Microsoft’s original Surface Book. It’s based on an Intel Skylake Core i7-6700u and has 16GB of LPDDR3 and a 512GB Samsung 950 Pro NVME drive. The Surface Book is running the 64-bit Windows 10 Pro Fall Creator’s Update.

I basically drove the machine for most of a week at CES, and on that Friday morning when I fired it up at home, I found that Microsoft had pushed out two pairs of firmware updates that address the Spectre and Meltdown vulnerabil­ities.

I’ll admit, I’m still trying to play catch-up on just what the hell is going on with Spectre and Meltdown, but this was a great opportunit­y to run before and after benchmarks on a production machine.

I know from reading Steve Walton’s write-up at Techspot ( go.pcworld.com/tspt) that the performanc­e of games and most Cpu-intensive apps doesn’t change. But Walton found storage read/write performanc­e to be an issue, so this was my first point of investigat­ion on the Surface Book. I started my tests with a not-yetpatched machine.

BEFORE THE SPECTRE AND MELTDOWN FIX

I started by running the default test for Crystaldis­kmark 5.5.0. It’s the slightly older version, but the results are still valid for two areas: small 4K reads and writes as well as 4K reads and writes using a queue depth of 32. Above is the result before Surface Firmware 91.1926.768.0 and 90.1837.256.0 were installed.

I made three repeated runs with two to five minutes of rest time in between to let the SSD return to normal temperatur­e. SSDS, as you may know, can slow when heated. This is one particular result, but representa­tive of the results I saw.

AFTER THE SPECTRE AND MELTDOWN FIX

Once I completed my tests, I was able to reboot the Surface Book and let the firmware patches install.

As you can see in the next chart, the sequential read and write performanc­e doesn’t change much (in fact, Crystaldis­kmark no longer uses a low-queue-depth sequential test).

But just as Techspot found, 4K performanc­e ain’t pretty. While 4K read performanc­e was similar, the write performanc­e dropped by 26 percent.

Far worse, though, 4K read and write with high queue depth take a performanc­e hit of 42 percent and 39 percent, respective­ly. Ouch.

As with the pre-patch state, I ran the test three times with similar results.

A MORE RELATABLE SCENARIO

Storage performanc­e hits in synthetic read/write tests, of course, can be difficult to relate to. So, to see how the patches manifested in performanc­e that’s easy to relate to, I also ran Principled Technologi­es WEBXPRT 2015 on the Surface Book, using the latest version of Microsoft Edge. WEBXPRT 2015 is a browser-based benchmark that measures performanc­e in various scenarios in HTML5 and Javascript.

Unpatched, I saw an overall score of 450. Once patched, the score dropped, though not substantia­lly, to 433. That’s about 4 percent slower. Intel’s own findings with that same test show about a 10 percent reduction.

So is the situation not as dire as the synthetic storage benchmarks make it out to be? Yes and no. We’re still very early in testing the patches, but it’s safe to assume that performanc­e drops will be dependent on what you actually do with your machine.

As Techspot found, most classic tests (such as pure 3D rendering) and most games won’t see a change. But the greater-than-20percent storage penalty that both Techspot and I observed will rear its head occasional­ly.

In fact, one test that Intel presents is BAPCO’S SYSMARK 2014 SE. One of the most advanced benchmarks around, SYSMARK uses

real-world applicatio­ns such as Word and Photoshop, and then runs them through tasks that mirror real-world activity.

Even better, BAPCO has developed a method for testing where only the response time of an action is measured. In Word, for example, old-time benchmarks would type and perform actions in Word well beyond what even the fastest typist could ever hit.

But SYSMARK 2014 SE measures the things that can truly annoy you, like how long it takes to start the applicatio­n, or have it perform a search and replace, or import photos.

As you can imagine, SYSMARK will lean more heavily on storage responsive­ness.

Intel’s tests on SYSMARK 2014 SE mostly indicate about an 8 percent overall hit, but in the details for the

System Responsive­ness test (where you’d expect the storage performanc­e to matter more), Intel says its seeing a 21 percent drop. Ouch.

We’ll try to independen­tly verify Intel’s results on our own builds, but everything I’m seeing so far says the performanc­e penalty will probably run the gamut from “no big deal” to “this is really testing my patience.” Again: It’ll come down to what you’re doing, and how you’re doing it.

If we’re talking an extra 500ms to launch an applicatio­n that takes 1,500ms to launch, no big deal. But if we’re talking 34 seconds to import or copy photos instead of 27 seconds, it’s going to get annoying really fast and that’s what scares me.

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 ??  ?? Crystaldis­kmark 5.5.0 performanc­e results on a Microsoft Surface Book before being patched for Meltdown and Spectre.
Crystaldis­kmark 5.5.0 performanc­e results on a Microsoft Surface Book before being patched for Meltdown and Spectre.
 ??  ?? Crystaldis­kmark 5.5.0 results on the Microsoft Surface Book once it had been updated for the Spectre and Meltdown exploits.
Crystaldis­kmark 5.5.0 results on the Microsoft Surface Book once it had been updated for the Spectre and Meltdown exploits.
 ??  ?? Before Meltdown and Spectre patch in WEBXPRT 2015.
Before Meltdown and Spectre patch in WEBXPRT 2015.
 ??  ?? Two sets of patches for the Surface Book address the Spectre and Meltdown exploits.
Two sets of patches for the Surface Book address the Spectre and Meltdown exploits.
 ??  ?? After Meltdown and Spectre patch in WEBXPRT 2015.
After Meltdown and Spectre patch in WEBXPRT 2015.

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