The Controller

Like Seagate, Western Digital didn’t make the controller inside their SSD. The SiliconEdge Blue uses a 3rd party controller but despite my prodding, WD wouldn’t tell me who made it. As SandForce has proven, the actually manufacturer of the controller is not as important as the firmware itself. That being said, I still wanted to know.

Despite having Western Digital’s logo printed on the controller, WD didn’t opt for a custom PCB on its drive:

I’ve seen this PCB somewhere before. Ah yes, PC Perspective’s review of the JMicron JMF618 based Kingston V Series SSD. Based on JMicron internals and manufactured by Toshiba, this is the latest from the company that was responsible for my obsession with weeding out SSDs in 2008. Update: Allyn tells me that the JMF618's unique feature is its support for Toshiba NAND. If you use Samsung NAND that makes the controller a JMF612.

The JMF618/612 are allegedly a lot better than the JMF602 that everyone was trying to push a couple of years ago, but this is my first experience with it. The good news is that Kingston sells its JMF618 based drive for less than $2.20 per GB. This means that we might see etailer pricing on the SiliconEdge Blue at roughly half of its MSRP.

Like most other consumer SSDs, Western Digital sets aside roughly 7% of the NAND flash on board for spare area to be used for cleaning and bad block allocation.

Sitting next to the WD branded JMF618/612 controller is a 64MB DDR2-800 DRAM made by ESMT. That’s not a ton of memory by any means, but it is ridiculously fast memory. By comparison Intel uses 32MB of PC133 SDRAM, offering 1/6 of the bandwidth. With that much memory off-chip, JMicron is most likely using the DDR2 DRAM as a cache for user data in addition to the mapping tables and block allocation algorithms. The more data you store off chip, the more bandwidth you need to service that data.


16 chips x 16GB Samsung MLC NAND Flash

Western Digital claims rights to an exclusive firmware with the SiliconEdge Blue. The initial firmware appears to be supplied by JMicron, but Western Digital has modified it to tune for compatibility. In theory that means that we won’t get the same performance out of the SiliconEdge Blue that we do from Kingston’s SSD that uses the same controller.

The JMF618/612 supports TRIM which is enabled on the SiliconEdge Blue. Western Digital won’t be offering a manual TRIM tool for non-Windows 7 OSes, stating that the performance of the drive never drops to a point where you’d need to manually TRIM it. I can’t say that I agree with that since I managed to make the drive perform quite poorly after hammering on it for a while:

But it does attempt to be fairly resilient and after being TRIMed it manages to stay very close to peak performance:

You can use the SiliconEdge Blue in a non-TRIM aware OS, but I’d recommend sticking with Windows 7 if possible.

Index Scrambling Data to Improve Reliability?
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  • chuckbam - Saturday, March 20, 2010 - link

    I buy Intel for the Intel SSD Toolbox utility. With win7, I load the Intel chipset inf, Matrix Storage Manager and am not sure if Trim still works.

    I am happy to see WD into this market. Prices need to come WAY DOWN!
    Reply
  • Sabresiberian - Saturday, March 13, 2010 - link

    As a great fan of the Raptor series drives, what I want from WD is the same concept in SSD: the top performance and super reliability it is. The down side of course in a VelociRaptor is its relative price - and, as expensive as SSDs still are, a comparable price for an SSD "VelociRaptor" would be extreme.

    Still, it's what I want, and I could certainly see me building a high-end system using smaller capacity WD SSD "Raptors" in Raid 0 for that extreme performance goofy people like me want to have. If I get an extra few grand handed to me, I would use larger drives, of course.

    Anyhoo, this drive is not what I want to see from WD (unless of course it really does kick reliability butt over its competitors). Hopefully by the time I build another high-end rig (just built one so it will be awhile, likely) WD will have what I want (or someone), a SSD successor to VelociRaptor mechanical hard drives.
    Reply
  • liquoredonlife - Wednesday, March 10, 2010 - link

    Great article Anand! Also thanks for reiterating the incompatibility with gen2 unibody macbook pro's and particular SSDs. Will you be able to test this SSD with your mbp? Reply
  • heulenwolf - Wednesday, March 10, 2010 - link

    Anand mentioned some possible convergence between magnetic and solid state drive firmware development. Could this mean the mythical hybrid drive is down the road somewhere? With single spindles holding in excess of 300 GB and SSDs not even filling the 2.5" form factor, isn't there room for both? If not both storage types in one drive then maybe both storage types in one drive slot? Then you could have the boot drive be the super fast SSD and the advantage of cheaper, higher-capacity storage of a single-spindle magnetic drive in a single laptop. I think this dual-drive approach could be a better solution than the hybrid drive until caching in drive controllers becomes smarter. Reply
  • GullLars - Sunday, March 07, 2010 - link

    These drives clearly don't support NCQ, as IOPS don't scale with QD.
    The rating of 5000 IOPS is about the same as the rating of a single NAND TSOP. You can literaly get the same random IOPS performance from a thumbnail USB drive.
    Reply
  • ky - Thursday, March 04, 2010 - link

    Can someone explain why there's a dropoff in performance between the 100GB and 50GB Mercury Extreme SSDs in the 4K Aligned random write test? Reply
  • cactusdog - Thursday, March 04, 2010 - link

    Oh well nothing to see here either. I dont see how they can justify the price. A SSD with a PCB and some chips should be cheaper to make than a mechanical hard drive with moving metal parts. Fair enough to pay a little extra for new tech but this is ridiculous. Reply
  • Hrel - Wednesday, March 03, 2010 - link

    I'd really like to see performance of two 7200rpm drives in a striped RAID thrown into these charts. So please get on that. Reply
  • 7Enigma - Thursday, March 04, 2010 - link

    I'll save you the time of waiting.

    -Sequential Read and Write: Near twice the performance of a single drive

    -Random 4K read/write: Just as bad as a single drive

    Fin~
    Reply
  • GeorgeH - Wednesday, March 03, 2010 - link

    Going from WD's HDD naming conventions I would expect average but reliable performance from a "Blue" SSD, and that appears to be exactly what they've delivered, albeit at a ridiculously high price.

    The WD SSD I'm really interested in is the "SiliconEdge Black", a drive that will hopefully be forthcoming after their sales division puts down the crack pipe and gets serious about SSD pricing.
    Reply

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