Corsair 4GB DDR2 XMS2 PC2-6400C5 TwinX (2x2GB) has different latency

Dela · 2 Feb 2008 at 18:44

A month ago I bought Corsair 4GB DDR2 XMS2 PC2-6400C5 TwinX (2x2GB) which had timings 5-5-5-12. Then the other day I bought an identical pair but they had timings of 5-5-5-18 (even though they were advertised as 5-5-5-12) and I can't get all four to work together. None of them are faulty and I've tried upping the voltages and nothing. Any ideas? Thanks

My specs

Q6600 @2.4GHz
GA-P35C-DS3R motherboard
8Gb RAM (Hopefully)
7800GT
Vista Home Premium 64-bit

Dela · 2 Feb 2008 at 19:45

It's strange, I can run three of them to get 6Gb but when I add the 4th it won't boot. It's doesn't seem to be a problem mixing the RAM until I run it in duel channel. What's the north bridge voltage? Is that the voltage for the CPU? Sorry bit of a noob.

Dela · 3 Feb 2008 at 12:45

Yeah I tried upping the MCH voltage. I tried +0.1V and then +0.2 and nothing happened. Was a bit too chicken to go any further as it could only be upped +0.1V more and it would be at its limit (+0.3V). My motherboard won't let me change latency timings so there's not a lot I can do. It's already been RMA as it was advertised with the wrong info. Cheers for your help guys.

Dela · 3 Feb 2008 at 18:12

Sweet! I'll give it ago. Thanks.

Dela · 3 Feb 2008 at 19:11

Well it did allow me to mess about with the timings but I still can't get it to boot with 4 sticks. It keeps turning off after about 10 secs then turning itself on again, then off etc... Never displays anything on the screen, it's just black.

Dela · 4 Feb 2008 at 20:18

Cheers for all your help guys. It has proved very useful. I think that the RAM is compatible with each other as I can run one of each in two banks (dual channel/ and not) and even two of one and one of another. It's only when all four are in use that it doesn't work. The computer goes into reset cyles every 10 seconds or so. It seems that some sort of under voltage is the problem, but that was the first thing I investigated. I've tried overvolting the RAM +0.3V hence it would be running at 2.1V (although Everest reported 2.0V) and still no joy. I'm gonna investigate it further and take on board all your help when I have a bit more time. Will keep you posted. Thanks again.