IC7 (-G) can you do FSB >285 AND 5:4 divider?

I have vmem modded my IC7-G , Prometeia cooling on the CPU, ThermalTake Tiger1 on the Nortbridge and everytime the thing freezes/locks-up when set to FSB 282 and 5:4 divider.

3DMark01 can do 1 run, the 2nd run freezes. When FSB set to 283 not even 1 run can pass.

I have been reading a lot of forums and I have not yet seen anyone with the IC7(-G) that can go higher and keep 3DMark (or games) stable...

Ofcourse I have tested all my components and all are good at even higher speeds. I think the limiting factor is the motherboard (the NorthBridge just can't handle the amount of traffic).

I have tried *every* setting in BIOS, but this 'wall' cannot be overcome.

What I would like to know, have you ever seen anyone with high FSB AND 5:4 divider?
I have seen lots of people around the same limit as me, but never seen anyone with FSB 290 or so AND 5:4 divider....

I run at 285, I can run at 290 if I relax my ram timings and raise my CPU voltage.

What type of ram do you use ? What timings ?

You have to have excellent RAM to run 285 FSB using the 5:4 ratio with dual channel, that's DDR456.

There are many people that hit 300,

BTW, 285 at 5:4 is 228mhz

I have seen plenty of people that have broken the 285 barrier with the new OCZ 3700 Gold. Sounds like you ram is crapping out on you.

Duh! Memory bus running at 228 X 2 (DDR is dual data rate) = DDR456.... do the math. If you have PC3500, then that's rated at DDR433. I've seen a few people hit 300 FSB, but most are using the 3:2 ratio, not 5:4 (which would be DDR480). The only RAM I've seen that can do that speed in dual channel mode is OCZ PC3700 Gold.

LOL My bad

My dislexic a$$ thought it saw 256 (meaning DDR512) when you put 456.

Anyhow, this is all true, you need great ram, even my Corsair pc3500 is my limiting factor. If I had better ram, I could do way better.

No, I tried it all...

FSB 281 5:4 divider (DDR 449) 2-2-2-5 stable as a rock.
FSB 282 5:4 divider (DDR 451) 2-2-2-5 only 1 run 3dmark stable
FSB 283 5:4 divider (DDR 453) not even 2.5-4-4-8 can do it.

Memory was okay upto DDR 480 (1:1) with 2-2-2-5

I'm sure it is the chipset/northbridge that can't take it anymore...

Try using the 3:2 ratio to make sure the RAM ain't the bottleneck. With dual channel mode, it's tough to run high DDR speeds when you're close to max overclock.