RAM speed overclocking question

[koocha]

Hi all

I'm running my Opteron 165 @ 2.58Ghz using a multiplier of 9 and an FSB of 287Mhz.

When I boot up it tells me my RAM is DDR 266 Dual Channel (it's set to auto speed in the BIOS). If I try to put it any higher it freezes when POSTing and the BIOS automatically resets itself to default settings.

Is there a way I can get my ram to run faster? It's that that's putting my Vista performance rating down to 4.5.

I've got 2 x 512Mb sticks of PC3200 (Corsair value I think) and 2 x 256Mb sticks of PC3700 (Twinmos).

Cheers

[shaithis]

What speed is your RAM actually running at tho? (CPUz will tell you this info)

Some boards work differently then others, but I would guess you are running it at around 190MHz (I got to that by FSB x Selected RAM speed / Rated RAM Speed...i.e. 287 x 266/400)

Seeing as PC3200 tops out at 200MHz FSB (400MHZ DDR), you don't have much room to increase this higher without manually relaxing the RAM timings and/or pushing the RAM voltage higher.

[koocha]

Thanks for the reply. I'll use CPUZ when I get home and let you know what it says.

The RAM is running at 2.7v which is the requirement for my PC3700 sticks.

If new ram is the way to go I'm having a hard time finding some. It all appears to be DDR2 now

[kalniel]

Just manually set the timings higher on the ram, especially try T2 rather than T1 for the cycle.

If you're ram speed is selected as 266 yet the FSB is 287 then the actual speed of the ram is something like 384, not far off it's rating of 400.

If you set it to the next one up (333?) the real speed would be 480 - quite possibly beyond the capability of the value select without vastly loosening latencies.

[shaithis]

On AMD systems, the speed of the CPU means more then the speed of the RAM when it comes to performance.

This is due to the memory controller being part of the CPU.

I wouldn't worry about the current RAM speed as it means so little in real-world performance.

[koocha]

here's my cpuz screenies:

[shaithis]

So, your RAM is running at 188MHz, thats only just shy of its rated speed (200).

If you push the RAM any further you would almost certainly have to increase the voltage to it and relax the timings, its probably not worth it.

You do have some room to try for a higher overclock tho

[manwithnoname]

If you are not going to run your ram faster than 188MHz, you might be able to run your ram at 2.5-3-3 instead of 2.5-4-4 as you have your PC3700 sticks underclocked.

Not sure what speed difference you will see.

You have your ram on a 14 div, is there a 13 you could set it to and clock the bus at 288mhz that would run the ram at ~200mhz?

[koocha]

So, your RAM is running at 188MHz, thats only just shy of its rated speed (200).

If you push the RAM any further you would almost certainly have to increase the voltage to it and relax the timings, its probably not worth it.

You do have some room to try for a higher overclock tho

I can't get any higher than 293 without it rebooting when it tries to load windows.

If you are not going to run your ram faster than 188MHz, you might be able to run your ram at 2.5-3-3 instead of 2.5-4-4 as you have your PC3700 sticks underclocked.

Not sure what speed difference you will see.

You have your ram on a 14 div, is there a 13 you could set it to and clock the bus at 288mhz that would run the ram at ~200mhz?

Thanks for the idea, but what you have just said may as well be in chinese. Don't have a clue. suppose I best leave it!

It's the 4.5 rating that Vista gives me that makes me mad. without that it should be 5.0 and that's limited by my processor

[kalniel]

It's the 4.5 rating that Vista gives me that makes me mad. without that it should be 5.0 and that's limited by my processor

Tell you what - the Hexus forum will give you a 5.0 rating. Better now?

[koocha]

Tell you what - the Hexus forum will give you a 5.0 rating. Better now?

Yes thanks!