Two SSD Options: SandForce and SanDisk

Like many OEMs, ASUS sources SSDs from two vendors for its Zenbook line: ADATA and SanDisk. Unlike Apple however, the division isn't random. ADATA supplies all 128GB drives while SanDisk handles the 256GB drives. The explanation is simple: ASUS needed a drive that could fit all of its NAND on a single side. SanDisk had a 256GB offering that met those needs; ADATA/SandForce did not.

ASUS didn't specify what SanDisk controller was in use on the 256GB drives, but I suspect it's the U100. ASUS supplied the following test data comparing the two SSDs:

Performance is actually comparable between the two, which is surprising. I'm going to see about getting my hands on a 256GB SanDisk model for comparison to verify for myself. The sample laptop we received comes with the 128GB ADATA drive, which performed quite well in our tests:

Granted you're looking at highly compressible datasets, but being able to break 500MB/s puts this drive up there with the standard desktop SF-2281 offerings.

If you caught our Zenbook teardown you may have noticed a firmware label on the ADATA drive indicating it was using SandForce firmware revision 3.2.2. Uhoh! SandForce just recently announced that there is a known bug in all version of the SF-2281 firmware prior to 3.3.2 that can cause BSODs. I asked ASUS when we'd see an updated firmware and why on earth it chose to ship a drive with a widely known bug.

During development, ASUS tested 100+ Zenbooks with 100+ samples of the ADATA drive. The testing included over 50,000 accumulated reliability tests including rapid sleep/wake cycles, 3DMark and other application based tests. In addition to pre-production testing, ASUS conducted additional testing on mass production units. Throughout this entire process ASUS didn't see any reliability issues with the SandForce drives and thus felt comfortable shipping with them. I should add that we have seen many cases where the SF BSOD bug simply won't appear on certain platforms, lending credibility to ASUS' claims that the SandForce drives proved stable during testing.

That being said, I'd still feel more comfortable with an upgrade to 3.3.2 if it turns out that this firmware revision does in fact fix a known issue with the drive.

I pointed out the obvious rework on the ADATA SSD to ASUS engineering. The team responded by saying the rework was implemented to reduce EMI, which was a bit too close to the margins before the change. The rework has since been incorporated into a surface mount component design which will ship in a future spin of the drive. I'm not a huge fan of reworks on shipping products but from time to time they do appear. The nature of the rework and quality of the workmanship are also important to keep in mind, both of which are less alarming in this case than others.

The Zenbook The Keyboard & Trackpad


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  • CallumS - Saturday, October 22, 2011 - link

    Looks like a brilliant design and in my opinion has better aesthetics than the MBA. What I would really like to see though is Thunderbolt or a decent alternative introduced across the line.

    Personally for basic web and coding I find ultra-portables perfectly capable at the task, especially with SSDs. However I would still like the option to plug in a maximum of two cables to get >FHD resolutions and everything else connected. I truly believe that including Thunderbolt was a brilliant idea for Apple. It really did open up a lot of opportunities.

    BTW: Never owned a Mac and can't use OSX due to work applications. Looking for the best Windows alternative or to purchase a MBA to run Windows 7. The best alternative at the moment that I am aware of being a Thinkpad x220/x1/T420s with SSDs and docking station.
  • kaiedmek - Saturday, October 22, 2011 - link

    A brilliant design!!! Come on, They just stole MBA design.... they didn't work on there own design, wished they did, but instead they just copied others design.
    To produce brilliant computer they should do their own design, so they can match the internal hardware with the design and of course the software performance.
  • CallumS - Sunday, October 23, 2011 - link

    I never said an original design. =)

    I do agree though, it does look far too much like the MBA. Probably more so than the Samsung 10.1 tablet and the iPad; Which was banned here in Australia.

    However there are key differences and as my post was pointing out, I believe these are to the advantage of the of the MBA; apart from aesthetics.

    I think it would also be naive to suggest that the MBA was a completely original design also. There were many other notebooks with similar shapes and ambitions. Apple did however put them together very nicely though. I certainly do respect Apple's ability to accomplish such tasks.

    Unfortunately not very helpful when most business applications are purely designed for the Windows environment at present. Hopefully in time we can see that change and some better innovation from Microsoft too. Windows 7 has certainly set a great foundation and Windows 8 is looking promising.
  • GeorgeH - Sunday, October 23, 2011 - link

    Yep, without Thunderbolt and a docking station that allows more connectivity and the ability to attach a real (and hopefully upgradeable) GPU I'm just not interested. Otherwise this is just a slightly more useful tablet - an expensive niche within a niche.

    So here's hoping that the Ivy Bridge refresh brings a better screen, Thunderbolt, and a reasonably priced (I'm looking at you, Sony) external and upgradeable GPU.
  • DanNeely - Sunday, October 23, 2011 - link

    It's the battery life that really disappoints me. I'd like something with more performance than my netbook; but my 1st gen models 6 hour battery never lasted me a full day at a convention. Reply
  • Roland00Address - Sunday, October 23, 2011 - link

    I dislike the term "cells" for laptop batteries for it doesn't really tell you the capacity of the battery like the term Whr does.

    A 6 cell battery for a laptop would usually have a 40 Whr to 60Whr. This laptop has a 35Whr battery.

    4 to 5 hours is pretty good for a 4 cell battery that is not running something dirt slow like atom
  • DanNeely - Sunday, October 23, 2011 - link

    the runtime isn't unreasonable for the CPU+battery combination; but it's well short of what I'd need to be able to retire my netbook for something a bit speedier. Reply
  • netmann - Saturday, October 22, 2011 - link

    Thanks for the great review as usual. Is there a chance the future update to this review would include performance comparison of Asus UX21 with 11-inch MacBook Air with Windows 7 (through Boot Camp) and OWC 6 GB/s SSD installed in it? I believe some of like the Apple hardware better than PC but prefer running Windows OS. Reply
  • vol7ron - Saturday, October 22, 2011 - link

    Great review, two things:

    1) I wouldn't trust ASUS testing - thinking back to how horrible it is to contact their support, and how they had issues with their mobo's for the C2D (and so many other things)

    2) It looks like the Skype images are on OSX, not Win7 :)
  • digitheatre - Monday, October 24, 2011 - link

    It is because they want to test the UX21's video camera quality, so the screenshot is captured from MBA :P Reply

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