FSB:DRAM ratio, when to use 1:1?

sanofi · 7 Apr 2008 at 00:47

I've seen some people use 1:1 for this and am just wondering if there is a particular reason to do this? I am using the default 5:6 atm with a 390FSB.

steve258 · 7 Apr 2008 at 02:54

When your RAM is not fast enough.

sanofi · 7 Apr 2008 at 18:33

I'm using OCZ PC2-6400C4 Dual Channel Platinum Revision 2 XTC Series DDR2, in general how far will I be able to push the FSB at this ratio?

steve258 · 7 Apr 2008 at 18:47

400FSB will push the RAM to DDR800 PC6400 at 1:1. But the OCZ kit generally overclocks well so it's most likely to do a lot more than 800Mhz.

At 390FSB 5:6 you're running your RAM at 936Mhz so it's already overclocked by a fair amount.

sanofi · 7 Apr 2008 at 19:42

steve258 said:
400FSB will push the RAM to DDR800 PC6400 at 1:1. But the OCZ kit generally overclocks well so it's most likely to do a lot more than 800Mhz.

At 390FSB 5:6 you're running your RAM at 936Mhz so it's already overclocked by a fair amount.

It's at 400FSB now, still at 5:6 and I'm running Orthos, so that makes it 480x2, 960DRAM, thats not too high is it?

steve258 · 7 Apr 2008 at 19:47

as long as the memory is stable then it's not too high

run some memtest as well (either the hci design one in windows or memtest86+) after orthos just to be sure.

sanofi · 7 Apr 2008 at 20:47

I had it at 400Mhz FSB at 1.2125V Vcore in the BIOS, 5:6 and 1.8V RAM voltage (according to CPUZ but I upped this before by 0.3V in the BIOS) and my e8200 hit 3.2Ghz but I would get blue screen errors.

I increased the Vcore more but still had crashes, so I lowered the FSB to 395 and it seems stable. What can I do to get more out of it?

sanofi · 7 Apr 2008 at 21:51

I increased the VDIMM by +0.4V so its not at 2.2V, and 3.2Ghz seems to be stable atm, is this too high of a voltage for the mem?

steve258 · 8 Apr 2008 at 00:23

2.2V is still ok if you have nice case airflow. But 960Mhz really is pushing the OCZ kit a bit too far and it's most likely what's holding your CPU overclock back. What timings is the RAM running at?

If you have the option to run 1:1 then I'd use that.

Roobubba · 8 Apr 2008 at 08:32

I don't quite get the need to run at 5:6 when you could do the same thing at 1:1. I'm guessing there must be some other benefit to running at this divider rather than 1:1, would someone mind explaining to me why that is?

Cheers in advance!

Roo

sanofi · 8 Apr 2008 at 22:22

steve258 said:
2.2V is still ok if you have nice case airflow. But 960Mhz really is pushing the OCZ kit a bit too far and it's most likely what's holding your CPU overclock back. What timings is the RAM running at?

If you have the option to run 1:1 then I'd use that.

I'm not quite sure where in the BIOS I can change the ratio.

Timings atm are 5 7 7 18, they are set to auto in the BIOS. I'm using the Gigabyte P31-DS3L.

I had a look and changed the DRAM frequency ration to 2.00 and that made it 800Mhz, the same as the FSB but it wouldn't boot and would revert back to an unclocked state.