What RAM is necessary? Overclocking

[mikeo01]

I bought Phenom II x6 1045T as you know and have found out that under certain FSB speeds one of my RAM decides to knock out and is unusable, sure it is detected but not in use.

Up to 285 my RAM is fine, but it seems over this and it can't handle the bus frequency. So it may be limiting my overclock

My board has the option from 100 ~ 600 FSB/HTT/BLCK whatever you want to call it.

So looking for RAM that will be capable of running on a high bus speed, maybe at 1333mhz or near 1600Mhz if I can get it.

I think I can push my Phenom further, other than that I would like to keep at 4Ghz with capable RAM.

Any suggestions?

Also, I know its in wrong section but additional question pointless to make another thread for, any way to properly cooling the VRM and NB area? The heatsinks are a funny shape so can't mount a fan on it properly.

[Terbinator]

When you're at 285MHz bus what is the RAM speed reported as? What RAM do you currently have at the minute?

[mikeo01]

1140mhz, which runs at 9-9-9-20 natively. The RAM is capable of running at 1524mhz at 10-10-10-24 according to the manufactures site.
Its made by Eudar.

[Terbinator]

In that case you're RAM isn't the bottleneck in terms of spec.

It could be your IMC (memory controller) needs more voltage and/or you've hit the natural limit for your chip without insane overlcocks and cooling. 285MHz is around average bus for the Phenom's, as far as i know.

If it is the limit - and it probably is - you could up the NB speed too as this gives a sizeable increase to X6 performance - even at stock clocks. If you can net around 2.6GHz (from 2GHz stock) on the NB you will be set.

[mikeo01]

I have tried upping the DRAM voltage to 1.6, upped the NB to 1.15 and both haven't worked.

Also my I found my Phenom is stable, 1.36vcore with 1.175 CPU/NB. It runs fine at 297 but that one stick of RAM doesn't work.

My NB runs at 2673mhz but it can run at 2970mhz if I give it more voltage.

I have noticed in Windows it says 8GB (4GB Usable). BIOS listed 4GB but has detected the other stick of RAM. After 290 on the bus only one RAM stick works, I tested it by leaving one stick in then swapping over. The one causes a non-POST LED and will not boot. The other RAM is fine at bus: 290+

I have tested it by increasing the FSB on the fly with ASUS utility. As I hit 290 it freezes. Now if I leave the "good" RAM in it doesn't have a problem with it.

[Terbinator]

I have tried upping the DRAM voltage to 1.6, upped the NB to 1.15 and both haven't worked.

Also my I found my Phenom is stable, 1.36 with 1.175 CPU/NB. It runs fine at 297 but that one stick of RAM doesn't work.

My NB runs at 2673mhz but it can run at 2970mhz if I give it more voltage.

I should note, after 290 on the bus only one of my RAM stick works in any DIMM slot, the other RAM will not work. No POST and LED indicates RAM error, if I swap them over I can run at 297 bus speed.

Dodgy RAM perhaps? Return everything to stock and run Memtest.

[mikeo01]

I will give it a go will post results back soon.

[mikeo01]

Just tested the RAM, all fine no errors?

[mikeo01]

Right no idea if its the RAM or motherboard having a hissy fit, but setting close to 289 with RAM > 1333mhz and it even freezes in the BIOS.

This is generic RAM, although it says on the site CAS 9 for 1600mhz it also says CAS 10 for high density only, well I have been setting that so not sure whats going on.

If I did upgrade my RAM whats the chances of it allowing a higher bus overclock? Sure I would love to get close to 4Ghz, but is it worth it? Not sure how much strain its putting on the NB, though it allows up to 600 FSB (who on earth would be able to get it even close to that)

I am going to try to settle for about 3.5Ghz at the moment which feels very quick

[JimmyBoy]

I have some Kingston hyper x ram that runs at 1600mhz happily, it wasn't expensive so if you do try some more ram and it doesn't help it's not too bad! Have you tried updating the bios? Could be a bug when reaching a certain fsb? Why not try swapping the ram over from one slot to the other then you'll see if the ram that previously didn't work at higher speeds works in the other known working slot, then you'd hopefully have your answer

[mikeo01]

Thanks for the reply, I will give that a shot. I have tried the dual channel configuration slots but not individual slots.

If it happens to unfortunately be the RAM what's best to go with, a single 8GB stick or use dual channel?

Would 1600mhz RAM be fine on a very high bus speed, I am thinking there's more head room because the RAM is designed for higher speeds.

Anyone heard of komputerbay? RAM I found its quite cheap for a single 8GB stick CL10

[scaryjim]

Hmmm, thought I'd dropped a reply in here but apparently I didn't click "post" *doh*

Basically, since it seems to be FSB sensitive I think it's more likely the IMC on the CPU rather than the RAM (the RAM shouldn't know what speed the FSB is running, only what speed it (the RAM) is being asked to run at). To eliminate this possibility drop the RAM multiplier down as far as it will go to eliminate the RAM as a potential source of error. It might also help to let the latency out to something like 11-11-11-30 as well, make sure the RAM is well within its limits.

Then, as JimmyBoy suggests, try the "good" RAM stick in each individual slot, to see if there's a pattern where it runs at higher FSB or not. Perhaps one channel of the IMC is more sensitive to FSB than the other (not sure if that's possible, but it's a working hypothesis ). Also, try the "bad" RAM stick in the slot the "good" RAM stick was in. The way you've described the problem in the OP, this sounds like the most obvious explanation.

If you do only have one good channel, then a) make sure your board can support 8GB sticks (I know my AM3 (785G) motherboard can't), and b) buy the fastest sticks you reasonably can, to compensate for being a memory channel down. Since you're not using integrated graphics it shouldn't make that big a difference, tbh.

[kalniel]

280+ is pretty high for the CPU clock - you could be hitting limits all over the place from HTT to IMC. If you're pushing the IMC then it could be more sensitive to discrepancies in RAM, and if you've got a weak stick that might be contributing.

Can't you just drop the RAM multiplier down to eliminate memory being the cause? Also drop HTT multiplier.

[mikeo01]

Thanks for the posts everyone, here's an update on what I tried and what's going on.

Threw the FSB back up to 297 where that one RAM "pretends" it doesn't want to be seen.

Good RAM results! It works in every slot ticking away quite nicely at 11-11-11-30 at 1188mhz.

Bad RAM results! It doesn't work in any slot, even if the timings are loosened to 11-11-11-30. It even runs at 1188mhz which is well below the rated.

Both sticks are rated at 1333mhz CL9, default timings at 1333mhz are 9-9-9-24. Though if its under this and set to auto the SPD seems to set these timings to 8-8-8-20. Just to clarify, both doesn't work.

Can it be one RAM is just weak?

The CPUNB set for this was 2673mhz with a voltage of 1.25 just to rule out the CPUNB being the problem. I have also tried 2000mhz cpu nb with default voltage but didn't work

Gave the vcore a reasonable voltage boost (1.4 llc on) to rule out the core causing issues.

So looks like the weakest of the two stick causes an issue. Mind I cannot run over 297 FSB so this may be a HTT limit or the RAM again, but either way it seems to be 290 is the complete limit for these RAM sticks.

Can quality RAM allow for higher/more stable HTT clocks? I know Phenoms love the cold, so going to cool this thing as possible.

Though on benchmarks they show dual channel sticks perform a lot better than single channel? Either way would a 1600mhz+ single 8GB stick cope under high fsb? I thought HTT increasing shouldn't affect RAM, but maybe the bus is too quick for it?

Either way, looks like that stick is the weaker of the two so 4Ghz overclock is a no go, not only that but the RAM may be on its limit even at 285 FSB.

I have to say, it isn't bad for value RAM. Just strange, because their site states you can run it at 1600mhz at 10-10-10-24

[mikeo01]

Right got my final overclock for now, 1100T speeds.

1.272vcore
CPUNB 2500Mhz @ 1.100 (stock)
Temps 47C max

Now just to sort out this RAM so I can hit that golden 4Ghz

Thanks for the help, a single 8GB stick may prove the best option

EDIT:
For the record, OCCT tested for 1.50Hrs
Prime95 blend for 2.30Hrs.

[mikeo01]

This is the RAM

It says it will not work with AM3 or AM3+? I thought all RAM was the same, Corsair Vengeance is XMS and XMP ready but they are supported. I thought RAM was just RAM at the end of the day, with some being more optimised for Intel.

The only reason I am looking at it is because it is cheap and will run at 1600mhz so I won't be restricted or limited when I up my FSB

I don't particularly want to pay a whack on RAM because the only reason I have 8GB is BF3 (Lags at 4GB, so made me upgrade)