Totally confused about overclocking RAM (divider)

[Bobby74213]

I put the standard settings in that the OCZ forum recommend and it seems to be memtest stable, but not prime. What I really don't understand is why everytime I make the slightest change it becomes unstable.

Here's what I have now.

3.3v, 2-2-2-5 @ 250 mhz.

If I up the mhz to 252 it immediately failes memtest.

Now if switch it to 3.6v, 2-3-3-8 @ 255 mhz. I doesn't fail in the first two minutes, but it eventually does fail memtest. A little better I guess.

I have two 20 mm fans strapped directly to the sticks and my case flow is pretty good with 4 80mm intakes and 7 80 mm exhaust fans.

Another thing I'm totally confused about is the divider. It doesn't seem to accurately calculate the mhz when i use it. For expample, when I set my HTT to 200 and divider to 5/4 I would assume my RAM would be running at 250 mhz, but it says it's running at 140 in memtest... Even when I use dividers like 9/10 (180) its way off.

The CPU was easy but the RAM's got me really confused. Any advice, links or personal experience with these sticks would be great.

[casecutter]

Re: Totally confused about overclocking RAM (divider)

Why are you running a ram divider? You should run it 1:1 with the HTT. The only time I run any ram dividers is when I am going for insane overclocks and my ram won't run past 261MHz. Also, what happens when you raise the voltage to 3.6V and run 2-2-2-5? I also tend to run 2-2-2-6 as I have more stability there. VX is very very picky about the timings and settings. To keep the CPU out of it when running memtest, just drop the HT or LDT to 3. Then run the ram 1:1 with the HTT. List all your settings.

[Bobby74213]

Re: Totally confused about overclocking RAM (divider)

In Genie Bios
250
auto
16 16
7
100
disable
1.450v
1.3000V
above VID 110%
1.30v
1.70v
3.3V

Dram Config
250
enable
2.0
02
05
02
10
16
02
03
02
03
1168, 1560, or 3120
auto (this option is not in the 704-2BT bios)
enabled
auto
0
Level 8 (normal 4 in 704-2BT)
Level 2
8ns
normal
6ns
256
disable
16
04
disable

I went through about six hours of memtext without an error with these settings.

When I set the HTT to 255 it fails test 5 after about two minutes and then gives me countless errors.

So I left the HTT at 255 and set the voltage to 3.6: same results.

Then I loosened the timings to 2-3-3-8 and it took about five minutes to fail test 5 in memtest.

I would think I would have a little more flexibility with these but maybe I'm just missing something. I'd rather not use a divider but it seemed the best way to maintain the cpu overclock and RAM at the same time.

[Yawgm0th]

Re: Totally confused about overclocking RAM (divider)

There's nothing wrong with using a divider on an Athlon 64. Increasing the "HTT" doesn't cause the system to make use of extra memory bandwidth (as it would with an Athlon XP's FSB, for example), so if you need or want to overclock the CPU without overclocking the RAM much/at all (or if you want to overclock the RAM more than the CPU), a divider is fine.

That said, Casecutter is right in that you shouldn't really need a divider.

[casecutter]

Re: Totally confused about overclocking RAM (divider)

It may not be the answer you want to hear, but that ram just may not run past 250MHz. This is the speed OCZ tests them too and the really aren't guaranteed to go faster. I say go back to the OCZ support forum and start a thread with your results and ask why you get errors so easily. I still say heat as two 20mm fans may not really do much. I run two 60MM 22CFM fans on my ram when I OC it. The cooler the ram, the better the results. That could also explain why it takes a few to fail as they begin to heat up.

I do believe failing test 5 is heat related. You should double check that with the OCZ guys. And I also still suggest running 2-2-2-6 instead of 2-2-2-5. I have had issues with 2-2-2-5 myself that dissapear with 2-2-2-6.

[Yawgm0th]

Re: Totally confused about overclocking RAM (divider)

I do believe failing test 5 is heat related. You should double check that with the OCZ guys. And I also still suggest running 2-2-2-6 instead of 2-2-2-5. I have had issues with 2-2-2-5 myself that dissapear with 2-2-2-6.

It might be here, but I know on different systems that failing test 5 isn't heat related. Test 5 is simply the most sensitive and the most common failed. I have RAM in my NF7-S that usually fails test 5, but the system never crashes or has any instability. It might have something to do with the fact that it's running different sticks in dual-channel, but still...

[Bobby74213]

Re: Totally confused about overclocking RAM (divider)

I'm not that dissappointed if it can only reach 250. I've got a diode monitoring heat on the ram. It runs around 30 C with the settings I posted. If I raise the voltage to 3.6 it gets up to 36-38 C under load. I don't really know what acceptable temperatures are for RAM, though.

If I just accept 250 mhz for the RAM then I have the cpu's max at:

226 x 13 = 2938 @ 1.63v

I used this tool to try to determine the best settings to incorporate both the cpu and RAM. But it seems I'm sacrificing a lot with any settings. What's makes more of a difference in gaming, overclocking the ram or processor?

This is the best I came up with:

255 x 11.5 = 2932

Because it's a half multi, the RAM would actually be running at 244 mhz, which means I'm losing a little performance but not a lot and the cpu practically at it's limit.

[Yawgm0th]

Re: Totally confused about overclocking RAM (divider)

Overclocking the processor shoud make a much larger difference than overclocking the RAM in almost any application. That said, it does depend on just how much overclocking you're talking about.

[dryadsoul]

Re: Totally confused about overclocking RAM (divider)

What the hell are your system specs as in:

Soltek SL-K890-Pro (939 PCIeX)
AMD Athlon 64 3000+ Winnie
280x9 @ 2520Mhz
2x512 OCZ Platinum EL Rev2 DDR400
Gigabyte GeForce 6600GT PCIeX
SunBeamTech NUUO 550W SLI
1xWDC 80Gb 2XMaxtor 250Gb
ST Apogee/DD Maze4/D5 Uninstalled

Ram size & version of OCZ, Mobo, HSF.....etc.

If you're running a DFI LP try dfi-street.com