RAM trouble

[linford585]

Hi, I have G.Skill 1066mhz RAM, 4gb(4x1gb) with Vista x64, model number F2-8500CL5-2GBPK. Timings are CL5-5-5-15, voltages are between 2.0 and 2.1V. I have the voltage manually set in my BIOS to 2.05V. I have a Q9450 CPU, currently overclocked to 3.2ghz, keeping its stock multiplier of 8x, and raising the bus speed to 400mhz, giving me a rated FSB of 1600MHZ, instead of my stock FSB of 1333 and stock clock frequency of 2.66.

My concern is, according to CPU-Z (1.48), my RAM's max bandwidth is PC2-6400, 400mhz, while it still knows its model number of F2-8500. In the memory tab, it lists my DRAM frequency as 480-481mhz, and my FSB:RAM ratio as 5:6. It also lists my timings correctly, showing 5-5-5-15. Im wondering why its running like PC2-6400 (800mhz) and not PC2-8500 (1066mhz) like it should be. I have found, that while my CPU is overclocked (Prime95 stable for 24 hours), its only stable leaving my ratio on auto, which through CPU-Z I can tell is setting it to 5:6. If I attempt to change it manually (doesn't actually list out ratios in my BIOS, but instead shows corresponding speeds based on the different ratios), my system becomes extremely unstable, and I get lucky if I can even open Prime95 before it crashes or hangs. I know the difference between 800 and 1066 may not matter a whole lot, but this isn't really my question. I would like it to run at 1066, and I'd appreciate the help.


System Specs:
BIOSTAR TForce TP45HP (rated FSB of 1600/1333 and a memory standard of DDR2 1200(O.C.)/1066)
ASUS 4870 512mb
Q9450 CPU
G.Skill F2-8500CL5-2GBPK
BFG 650 watt PSU

Thanks!

[kens30]

Re: RAM trouble

DDR2 1066 memory is actually 800mhz memory overclocked and tested to run at 1066mhz 5-5-5-15 stable.And you also say that cpuz is displaying your dram frequency as 480mhz. Since your mem is ddr2 it is running at twice that amount 2x480 = 960mhz that is the actual speed your memory is running at.And for your system instability at other fsb:ram ratio make sure you are not exceeding 533mhz on mem that x2 will give you 1066.

[Lsdmeasap]

Re: RAM trouble

Thanks Kens30, that is for sure correct

[linford585]

Re: RAM trouble

Thanks! I've been reading around, and I believe my RAM clock is what is called "linked," as I cant change it to exactly whatever I want, but I can change it to presets. Even if I set it to DDR2 960, like it puts it at when its on auto, my computer will not boot. However, if I disable "DDR2 Enhance mode" (change from auto to disable, and I'm not sure what that is anyway), I can then boot up fine while its selected on DDR2 960. I went back, following what you said, and chose the highest amount I could without going over 533, which was DDR2 1000, leaving DDR2 Enhance disabled, and my computer successfully POSTs, but windows fails to start up. I am now typing this, after everything is fully stable, manually set on DDR2 960, and DDR2 Enhance disabled.

Any thoughts? (also, what does DDR2 Enhance mode do?)
Thanks again.

Edit:
I still want to try to get to 1066 (or at least 1000, in which I'm thinking now is all I can do), but in the mean time, I was reading about RAM timings, and decided to try to lower them. I got it stable with memtest to 4-4-4-12, and 2T for a command rate. Changing my CR at all made my computer not POST, even when I tried 3T, so I left it on auto, which from memset, and CPU-z, show 2T. When I lowered my timings, I put DDR2 Enhance, and my RAM clock set on auto, which still gives me 480mhz (960), but I just didn't want any other variables possibly conflicting with what I was changing.