IC7 and 2x256 Corsair XMS pc3500 problems.

Hi!

Just got myself 2 sticks of 256mb Corsair XMS pc3500 version 1.1.

275 fsb , 5:4 divider (ddr440) , vdimm 2.8, timings by SPD (2-3-3-6) .No errors at all.(prime for hours and memtest)

280 fsb , 5:4 divider (ddr448), vdimm 2.8, timings by SPD (2-3-3-6) .not stable in windows and in memtest.

284 fsb , 5:4 divider (ddr454), vdimm 2.8 , timings by SPD (2-3-3-6) . Reboots at winxp loading screen.

284 fsb , 3:2 divider (ddr378) , vdimm 2.6 , timings by SPD (2-3-3-6). Rock stable with prime and memtest.

All the ram timings above by SPD was taken from CpuZ.

I cant seem to figure out why i cant run my rams in dual mode with the 5:4 divider at 284 fsb. Ive run all the test above with the 2 last option in game accelerator disabled. (Command Per Clock and Read Delay Adjust.) I`ve even tried each stick with single channel mode on 284 fsb with the 5:4 divider 2-3-3-6, 2.8vdimm and it worked perfectly fine.

Everytime i try to change the RAM timings my board wont post at all even at the most relaxed timings 2.5-3-3-7 . The board will only posts when the ram timings are set to SPD (default).

Any help would be much appreciated. And ohh yah the rest of my rig is in my sig!!

I assume you have done the vmem mod?
Otherwise it would be almost impossible for the Corsair to get those speeds...


edit: you have tested in single channel I see, so it could also be your northbridge that's maxed out...
My limit is at FSB 282 for 3dmark stable. The IC7 is just maxed out with the 5:4 divider , or so it seems at least in my situation...

Thanx for the reply Vatt, maybe i should get myself a zalman NB cooler this weekend.

Why is it impossible for the corsairs to run at ddr454, its rated at ddr433 and im sure i can and will do ddr454 with at least 2.8 vdimm and relaxed timings.

Could it be a PSU limiting factor? Because i have an entry level psu rated at 420watt. Maybe when i was testing it using single channel it uses less power when running it with dual channel.

My limit is at FSB 282 for 3dmark stable. The IC7 is just maxed out with the 5:4 divider

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Nice, i wish i could do at least 282 fsb stable with the 5:4divider like yours but i just cant. I know my CPU will max out at 284 fsb on default vcore.

Dual Channel is a lot thougher, so if a stick is working fine in single channel, it is not to say that it will run at the same speeds in dual channel.

I have a Prometeia cooled CPU and the CPU is capable of FSB far beyond FSB 295 ! In my case, it is the board that is the limiting factor (at FSB 282)

My board just cannot do more than FSB 282 with 5:4 divider. The Northbridge just can't handle it...

I have XMS 3500 , just like you, I have performed the vmem mod so I have 3.1 volt running through the DIMMs, and nothing helped. I have a ThermalTake Tiger1 for NB cooling, and it didn't help. Perhaps deepfreezing the NB would give me some extra FSB's....

Perhaps deepfreezing the NB would give me some extra FSB's

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LOL that would be wayyy to wickedd!! youve got an awesome setup there with the prommie and everythin`, too bad that the board is holding you back.

Hmm , ive been doin some thinkin too about my mobo that cant handle high fsbs with the 5:4 divider in dual channel mode. Maybe i`d get the same performance too if i RMA this board and get another. So no point in doin that. Maybe i should try the springdale board . It costs much cheaper and it wouldnt hurt if i have a go with it just to run some tests. And i can sell it later off.