Overclocking
Ahh, now we come back to what I was talking about before. If you remember, dropping from CAS2 to CAS3 is a simple way to let your ram run at a few more MHz. You can see from the graph above the difference that going from 100MHz CAS2 to 133MHz CAS3 produces - even though the CAS3 setting is slowing the ram down, the MHz speed has increased enough to not only overcome that delay but to produce a healthy overall speed increase. Given that the Corsair can do 133MHz @ CAS2 without being overclocked at all, we now have a lot of headroom available for overclocking the SDRAM subsystem. Once we hit the ram's limit at CAS2, we can drop to CAS3 and keep cranking it up. So, how fast can it go at CAS2?

On the KA7 I managed to get the Corsair stick running at 160MHz @ CAS2. This is 117Mhz FSB with the +3 MHz option, ram running at FSB+PCI (120 + 40 for a total of 160MHz). The Athlon's core was at 1080MHz by this stage, watercooled at 1.8v. 160MHz @ CAS2 is, quite frankly, spectacular - check out this Sandra memory benchmark:

The only time I've seen a Sandra benchmark higher than that is in some pre-release Willamette (Pentium4) shots - but it's got a 400MHz FSB. With this setting I was getting nearly 140fps in the Q3 timedemo. After about 3 runs of the timedemo I started getting some errors but I suspect this was due to the video card not coping with the high AGP speed, not an SDRAM problem. Clocking it back to 117MHz, with the ram at 156MHz, it was rock-stable. This is still with "Turbo" timing and 4-way interleaving on - the fastest timing settings available.

And, the CAS3 setting? Well, embarrassingly enough, I can't tell you. I don't have a motherboard here capable of reaching this ram's CAS3 limit. The KA7 is only stable up to about 120MHz, so running the ram at 160MHz - and we've seen the Corsair do that at CAS2. Any higher and the board boots ok, but reboots as soon as you try to do anything stressful - but I experienced this before I got the Corsair, so it's most likely an issue with the motherboard or chipset. My trusty Soyo SY-6VBA-133 is only capable of running ram at up to 155MHz, and the other testbed is a BX-based motherboard - don't even think about ram speeds this high. Suffice to say, this stick of ram proved capable of taking all I could throw at it with ease, and it's not often you hear that around here..

Compatability / Reliability
I remarked in my KA7 review that I was having trouble with the KingMax PC133 CAS3 ram I was using for testing. Since then I have been informed that KingMax acknowledge an issue with the pre-v1.2 sticks and Athlon motherboards, and may even under some circumstances exchange sticks for a later revision. My stick is a v1.1, so perhaps my comments of compatability issues are a little unfair. Regardless, this same stick also led me to think the Soyo SY-6VBA-133, a Slot1 (non-Athlon) motherboard, was faulty when I first got it. Spontaneous reboots and extremely sporadic performance, long pauses in games etc were a common occurrence when using this ram. I had the same problems with a v1.0 64MB stick. With the Corsair these problems simply vanished in both motherboards.

Reading the Corsair spec sheets and website, you'd think they were specifying parts for an artificial heart, not a component for somebody to slap into their PC - but there's the distinction again. Corsair have for a long time been targetting their products at the high-end - servers, serious workstation machines and the like. Their primary design goal is NOT speed, it's reliability. Only quite recently with the falling of ram prices and the higher availability of ultra-high-speed CPU's have they brought their focus to the home user. They're still parts for enthusiasts - you won't discover Corsair in the bags of generic ram at your local clone shop - but they bring with them the history and experience of a very specialised high-end memory supplier.

This is all backed by Corsair's lifetime warranty. If the stick ever dies, send it back to them and they'll replace it.

Conclusions
I had previously told myself I wasn't going to buy any more ram until DDR266 became available, with motherboards to support it. However the need to build a new server for this site used up some of my ram stash and the problems with the KingMax stopping me using the KA7 to it's full potential were starting to erode my conviction.. after playing with this Corsair stick I couldn't let it go back. I did something I only very rarely do - I used my own real money, and bought the review unit. Surely there can be no higher recommendation than that.

The good news for Australian readers is that Jim Baker from Realtime Systems, the Australian official Corsair distributor, is organising a group purchase of this memory at a reduced price. If you're interested, head on over to this thread in the forums for details.