Dual Channel more sensitive to overclocking?

danahata · Apr 19, 2005

I was just wondering if running in Dual Channel inherently is more problematic when it comes to overclocking. The reason I want to know is because I just bought the second stick of RAM (overclocked single channel worked fine) and now the system is kind of erratically unstable- sometimes it fails to POST, sometimes it works fine, sometimes it has memory errors, sometimes not. The only way I could get it completely stable is to run it at the stock speed of 200mhz

.

And, yes, they are the exact same model and brand of DIMM.

GoldenTiger · Apr 19, 2005

Yes, Dual Channel mode is more stressful for overclocking, and generally results in lower overall stable clock rates.

Super Nade · Apr 19, 2005

danahata said:
I was just wondering if running in Dual Channel inherently is more problematic when it comes to overclocking. The reason I want to know is because I just bought the second stick of RAM (overclocked single channel worked fine) and now the system is kind of erratically unstable- sometimes it fails to POST, sometimes it works fine, sometimes it has memory errors, sometimes not. The only way I could get it completely stable is to run it at the stock speed of 200mhz .

And, yes, they are the exact same model and brand of DIMM.

Welcome to the Forums, Mate!

Running dual channel introduces additional overhead, i.e it stresses the on-die memory controller. However, in your case, the problems you face seem to stem from the two sticks not being matched (I hope they have the same timings in the SPD table).

Matched sticks are essential for dual channel operation. If you could post the SPD (and your BIOS settings) on both sticks, it will tell us for sure if that is indeed your problem. Sometimes, one is not guarenteed DC operation by buying sticks seperately. That is why DC kits are sold.

Finally, do you still get the errors when you lower your OC by say 30MHz?

Hope this helps,

S-N

danahata · Apr 20, 2005

As far as I know, they have the exact same timings, given that they are the exact same brand and model number. They are both Geil PC3200 1gb Value DIMMS, capable of 3-8-4-4 (I know they suck, but I'm poor). My RAM timings are set to that in the BIOS as well.

After installing the second DIMM, and noticing problems POSTing at 230mhz, I tried lowering to 220mhz, and still sometimes had a POST problem. I then lowered to 215mhz, and more of the same.

I got discouraged at that point and brought it back down to stock 200mhz, and everything is fine.

But I am not overclocked now.

Will burning the second stick in help?

Super Nade · Apr 20, 2005

It would to a certain extent, but don't expect anything too dramatie (i.e performance on par with 1 stick). A 20MHz drop in OC freq is quite normal and in fact quite pronounced in the case of Value RAM. This is because you have no overclocking head-room with regards to timings (you can't relax them anymore) or freq (they are value RAM, binned as such for a reason

).

Now, you could pump a bit more voltage into it and see if that helps.

Mate, please post the specs on your rig. Maybe there are other reasons for your problems

danahata · Apr 20, 2005

Athlon 64 3500+ Winchester
ASUS A8V-E Deluxe BIOS Rev. 1004
ATI Radeon x800 XL PCI-e
2gb RAM (2x1gb PC3200 GEIL Value Series) @1.85v and 3-8-4-4 timings
1 74g Raptor (SATA)
Zalman heatsink/fan
Antec Sonata case

I just noticed the timings were set to 'Auto', and I'm manually setting them to the default 3-8-4-4 now to test with.

UPDATE: I manually set the timings to 3-8-4-4, and still get the "Overclock fail or POST interrupted" message at boot.

Super Nade · Apr 20, 2005

Mate,

I suppose you mean 2.85V, right? What happens if you bump it up to 2.9V? I hope you are using the latest stable BIOS (1007, I think).

danahata · Apr 20, 2005

Yeah, sorry I meant 2.85v. I have BIOS rev 1004 (this is the A8V-E deluxe).

One thing I noticed is that my LDT frequency was set to 'AUTO'. I wonder if that means the BIOS was just 'automatically' setting it to x5 (In which case I would have been running in the unstable range of 1150mhz during my overclock). In any case, I set it manually to 800mhz (the options were 1000mhz, 800mhz, 600mhz, etc). I don't know why they say 1000mhz, 800mhz, etc, because it's not really true, and it's misleading- they should say the multiples (i.e. 5x, 4x, 3x, etc) because if you set it to 1000mhz and you overclock the FSB, you don't actually get 1000mhz, you get 5x the FSB frequency.

So I'm currently testing with a 4x LDT multiplier and seeing how far I can take up the FSB speed with a 2.85 voltage. If memtest starts erroring, I'll try bumping up the DIMM voltage to 2.9v.

danahata · Apr 20, 2005

Anyway, I'm at LDT x4, FSB 232, multiplier 11, memtest86 showing no errors after 3 iterations (1.5 hours), and I occasionally get a message upon booting:

***** Warning: System BOOT Fail *****
Your system maybe OverClock fail or POST interrupted.
Please enter setup to load default and reboot again.

I get this message maybe 1 out of every 3 boots. I'm not sure exactly what it means, and I'm wondering if I can just "press F1 to continue" without any harm?

Eldonko · Apr 20, 2005

If I remember correctly the A8V is weird for LDT. When I had one the only setting that would work was 1000Mhz, and at this setting LDT would adjust automatically. Take a look at Sandra or a program that shows HTF, it will likely be auto adjusting.

My guess would be your RAM probably has no OCing room when in dual channel.

Eldonko · Apr 20, 2005

That may also just be the infamous cold boot problem, if you can boot using f1 I think it will be ok. Both my and my roommates A8Vs do the same thing =/

danahata · Apr 20, 2005

This is a long shot, but I wonder if it has anything to do with my PCI-express not being locked down. I locked down my pci/agp port, but didn't lock down the pci-e because I didn't see the need to. I'm thinking maybe the graphics card hardware is crapping out occasionally when the BIOS POST tries to check it upon booting, since the pci-e is overclocked?

UPDATE: Nope, I tried disabling syncing the PCI-e to the CPU, still occasionally get boot failures. Nice try.

Super Nade · Apr 20, 2005

Mate,
I'm not familiar with the A8V-E, but I think the PCIE freq should be locked to 100MHz or 101MHz. Also look for a SATA freq. I think that needs to be locked too. Not sure about the numbers.

As for the cold boot problems, unfortunately ASUS have not found a fix for that yet. I see/saw it often with my A8V. Its not a critical flaw, but can be a bit annoying.

danahata · Apr 20, 2005

Ok, just to verify before I sign off for awhile- I can just continue to boot when I get that Overclock fail message, and you guys get that all the time? It doesn't indicate anything seriously wrong if it only happens occasionally?

Sorry for my paranoia.

Eldonko · Apr 20, 2005

Happens to my A8V 80% of the time if my rig is off long enough to cool down. Funny thing is that it only happens when OCed, however the OC is totally stable once you get up and running.

nstabl · Apr 20, 2005

Eldonko said:
Happens to my A8V 80% of the time if my rig is off long enough to cool down. Funny thing is that it only happens when OCed, however the OC is totally stable once you get up and running.

look at is as starting a race car engine

hard to get it warmed up but once its there its 110%

Edit: Only going to 220??? ehh, try running your ram 5:4 and start over. This is the easiest way to find out if your ram is your bottleneck, PM with any ???'s I'm thinking higher... wayyy higher

after all, you're at ocforums baby!!

--nstabl

Super Nade · Apr 20, 2005

^^ I think so too.

I sympathise, n wait emphatise with you, mate. I ran my rig on a 512 stick of PC2700. It was a terrible experience. I can move data in and out faster with my bare hands

However, the fun lies in pushing sad components to perform like champs. I hope we are able to help you out with that. Do not despair!

after all, you're at ocforums baby!!

danahata · Apr 20, 2005

Thanks. I think that the overclock/POST error is just some problem peculiar to these boards, and that I can keep pushing it while ignoring the error.

Super Nade · Apr 20, 2005

Actually,

These probles seem to afflict ASUS +VIA boards. I'm just speculating based on earlier experience. It would be nice if more people could confirm my suspicions.

Anyway, good luck with your OC :beer:

S-N

jblostsoul · May 2, 2005

I have a question for you guys. I have Geil dual channel 512(256x2). I am poor as well.lol. Anyway I also have a stick of vantec 256. Now I know that the Geil is 400 and the vantec only 333. So my question is this. What is going to give me a better speed? Putting the vantec in or leaving it out? And it will make it more unstable for OC'ing with it in right?

JB

Dual Channel more sensitive to overclocking?

Registered

Member

† SU(3) Moderator †

Registered

† SU(3) Moderator †

Registered

† SU(3) Moderator †

Registered

Registered

Revolutionary Mule

Revolutionary Mule

Registered

† SU(3) Moderator †

Registered

Revolutionary Mule

Member

† SU(3) Moderator †

Registered

† SU(3) Moderator †

Registered

Similar threads