IP35-Pro and Corsair Twin2x 6400C4

[Mutley]

Hi,

I've got 2GB of the above mentioned RAM installed in my nice shiny new Abit IP35-Pro motherboard.

The RAM is installed in DRAM slots 1 and 3, and appears correctly in the BIOS. The BIOS by default is set to use the SPD timings from the RAM, which according to CPU-Z comes out as 5-5-5-18.

I've tried setting the timings manually to 4-4-4-12 (the timings shown on the RAM itself), but when I do this, and reboot, the machine hangs, and won't even POST.

My guess is that I may be changing the wrong timing values in the BIOS. Below is what I change, I wonder if someone could check what I've changed, and tell me if I'm doing anything wrong?

CAS Latency Time (tCL) - 4
RAS# to CAS# Delay (tRCD) - 4
RAS# Precharge (tRP) - 4
Precharge Dealy (tRAS) - 12

Everything else (as regards voltages, FSB etc) is default.

Thanks!

[BUFF]

check the RAM voltage - at 4-4-4/800 iirc it should be 2.1V for that RAM.

[Mutley]

really? Default is 1.8v on the motherboard. How do you know what the voltage should be?

Also, have I changed the right settings?

[StoX]

look up your RAM on the Corsair website and it'll have the recommended setting

[BUFF]

1.8V is the JEDEC spec but for Corsair 6400C4 the tested voltage at 4-4-4-/800 is 2.1V.

[StoX]

As above, and if in doubt it can be confirmed at:
http://www.corsairmemory.com/products/xms2.aspx

or the official product datasheet for the type you specified in the first post:
http://www.corsairmemory.com/_datash...048-6400C4.pdf

[Mutley]

Thanks to you both, StoX and BUFF, very helpful. Just a littlle a loss as to why the default voltage for those timing isn't printed on the RAM.
I've since corrected the voltage to 2.1v and all is good - thanks again!

[StoX]

I know OCZ print the voltage on the RAM, and Corsair may have used to?? Perhaps that is something they should do - might be worth mentioning in their forums for future products

[SteveCliff]

I too had the same problem with the voltage being set to 1.8v rather than 2.1v. Although the 1.8v is as per JEDEC specs I'd kind of presumed that the SPD information would contain the required voltage setting so that the M/B would be able to properly "auto" set the config. Unless the SPD does of course and it's the M/B that ignores the setting?

Anyway - @ 2.1v mine is working a treat - thankfully!

P.S. I *think* the 2.1v is printed on the Corsair sticks - just not very nicely. I think you'll find "2.1" at the end of the code number on the sticker. I'm guessing that this is a reference to the voltage?

[StoX]

P.S. I *think* the 2.1v is printed on the Corsair sticks - just not very nicely. I think you'll find "2.1" at the end of the code number on the sticker. I'm guessing that this is a reference to the voltage?

I thought that was the version number...

[gilgamesh]

I know OCZ print the voltage on the RAM, and Corsair may have used to?? Perhaps that is something they should do - might be worth mentioning in their forums for future products

they so , ihave this ram and it is printed, on the purple sicker label.


gilgamesh

[Fabrice]

Hi guys,
Instead of creating a new thread, i thought i would continue this one.

Anyway, i am a novice when it comes to changing BIOS settings like CPU clocking, Voltages and DRAM Timing.

I have TWIN2X2048-6400C4 and i've been told by Scan that i need to set the RAM at 2.10V with latency timing 4-4-4-12.

Well, i can change the RAM voltage with the option User Define in uGuru under DDR2 Voltage by increasing it from Auto (1.8V) to 2.10V.
But Scan says there is little point doing that unless the Latency Timing is set to 4-4-4-12.
However, i have serious doubts about how to change that.
Reading the first post by Mutley:

CAS Latency Time (tCL) - 4
RAS# to CAS# Delay (tRCD) - 4
RAS# Precharge (tRP) - 4
Precharge Dealy (tRAS) - 12

Is this definitely the way to set it? I just want to make sure i don't do something stupid.
Shall i leave the following on Auto?

• Refresh Cycle Time (tRFC)
• Write Recovery Time (tWR)
• Write to Read Delay (tWTR)
• Act to Act Time (tRRD)
• Read to Precharge (tRTP)

Many thanks,

Fabrice