Earlier this month my Crucial RealSSD C300 died in the middle of testing for AMD’s 890GX launch. This was a problem for two reasons:
1) Crucial’s RealSSD C300 is currently shipping and selling to paying customers. The 256GB drive costs $799.
2) AMD’s 890GX is the first chipset to natively support 6Gbps SATA. The C300 is the first SSD to natively support the standard as well. Butter, meet toast.
Since then, Crucial dispatched a new drive and discovered what happened to my first drive (more on this in a separate update). While waiting for the autopsy report, I decided to look at 890GX 6Gbps performance since it was absent from my original review.
AMD's SB850 with Native 6Gbps SATA
In the 890GX review I found that AMD’s new South Bridge, the SB850, wasn’t quite as fast as Intel’s ICH/PCH when dealing with the latest crop of high performance SSDs. My concerns were particularly about high bandwidth or high IOPS situations, admittedly things that you only bump into if you’re spending a good amount of money on an SSD. Case in point, here is OCZ’s Vertex LE running on an AMD 890GX compared to an Intel X58:
My concern was that if 3Gbps SSDs were underperfoming on the SB850, then 6Gbps SSDs definitely would.
Other reviewers had mixed results with the SB850. Some boards did well while others did worse. I also discovered that AMD’s own internal testing is done on an internal reference board with both Cool’n’Quiet and SB power management disabled, which is why disabling CnQ improved performance in my results. As far as why AMD does any of its own internal testing in such a way, your guess is as good as mine.
I received an ASUS 890GX board for this followup and updated to the latest BIOS on that board. That didn’t fix my performance problems. Using AMD’s latest SB850 AHCI drivers however (220.127.116.11).
All performance improved, but we’re still looking at lower performance compared to Intel’s 3Gbps SATA controller except for random read speed. Random read speed is faster on the 890GX (but slower than X58).
The best part of it all is that I no longer had to disable CnQ or C1E to get this performance. I will note that my performance is still lower than what AMD is getting on its internal reference board and the performance from 3rd party boards varies significantly from one board to the next depending on board and BIOS revisions. But at least we’re getting somewhere.
In testing the 890GX, I decided to look into how Intel’s chipsets perform with this new wave of high performance SSDs. It’s not as straightforward as you’d think.