**Official DFI LanParty UT 790FX-M2R Review/Overclock/Guide Thread**

[Rammsteiner]

Hmmm,

lol.

I decided to give my 4x1GB OCing one more try. I upped Voltage to 2.3V and used (10x350)/6 and it friggin booted up. Though couldnt get it to even finish 32M for 3 tests. Upped to 2.35V still no go. At that point I decided to stop it since D9's, at least like a year ago, liked the die after a few months of high Voltage. Though Ive no clue whether that was due to bad PCB/memory controllers (actually only saw this by people with Intel boards...).

Not taking the risk but maybe 3.4V would have made it. Though the little I could test with Everest showed good results, with untweaked subtimings 36.0 ns latency, 11.5GB read/write.

But as I said I dont really feel like to go higher than 2.35V. I know the memory wont die instantly but if I could manage to get it stable I'd be tempted to run it 24/7 while Im not so sure how long the RAM would survive. They weren't really hot to touch though at 2.35V but still.

Most likely this amount of Volt is needed as Im running 4 DIMMs.

[Rammsteiner]

Anyone played with the Drive Strenght settings for RAM yet? It used to improve OC'ing but then again I heard high Drive Strength can kill D9's fairly quick. Though Ive no clue whether 2.0x is high or 1.0x is high

[KTE]

Anyone played with the Drive Strenght settings for RAM yet?

Yep, it can increase oc/stability. Just have a high MaxAsyncLatency value and you should be good. If drive strength is incorrect, the system should tell you at bootup when it performs the calculations.

Also, for anyone running P95 and having it stable and later getting freezes/lockups do this: open up AOD, monitor every core. keep your eye on it and what the cores are fluctuating to. I bet if it was 100% stable and you're sure of this but you start getting freezes, there must be PLL movement, i.e. 2.6G set must be shooting up past 2.7G for a quick second and causing lockups.

Just keep an eye on your cores for a while to see if there's any large fluctuation; it'll occur at idle, not under load.

[Iketh]

Yep, it can increase oc/stability. Just have a high MaxAsyncLatency value and you should be good. If drive strength is incorrect, the system should tell you at bootup when it performs the calculations.

Also, for anyone running P95 and having it stable and later getting freezes/lockups do this: open up AOD, monitor every core. keep your eye on it and what the cores are fluctuating to. I bet if it was 100% stable and you're sure of this but you start getting freezes, there must be PLL movement, i.e. 2.6G set must be shooting up past 2.7G for a quick second and causing lockups.

Just keep an eye on your cores for a while to see if there's any large fluctuation; it'll occur at idle, not under load.

lemme understand this better... u talking about 2.6GHz overclock right? and at idle a core might speed to 2.7GHz????

what does PLL stand for?

[Mathos]

lemme understand this better... u talking about 2.6GHz overclock right? and at idle a core might speed to 2.7GHz????

what does PLL stand for?

Phase Lock Loop circuitry. It's what works your HT Ref clock at 200Mhz. If there is a jitter in the signal that it puts out, or a spike it will effect the cores as well.

[Mathos]

Hmmm thats interesting infor KTE. I had my 9600 BE running at 2.7Ghz stable at 1.262v. Would boot fine, ran prime 95 stable for 24 hours. Stable in all benchies, like 3dmark06 and pcmark05. But, every once in a while after restarting for unknown reasons when I would go to start up Coretemp, or Everest to monitor temps it would lock those programs and refuse to load them. Granted that was also on 1.2 Bios on the k9a2 plat, so any gain from being at 2.7 was wiped out by the TLB fix. Rolled back to 1.13 to get away from TLB fix, and ended up having to knock the OC down to 2.5 at 1.25v for full stability.

Someone on Toms hardware has a theory that part of the Phenom's issue is a possible hotspot in the die, revolving around either the Northbridge or L3 cache. I do believe that the individual core readings that coretemp shows are correct. Under full load at 2.7 my cores were staying below 31c, but CPU temp according to everest was running and staying below 40c full load on all 4 cores.. So that temp difference between the cores and CPU has to be coming from somewhere.

[Iketh]

Hmmm thats interesting infor KTE. I had my 9600 BE running at 2.7Ghz stable at 1.262v. Would boot fine, ran prime 95 stable for 24 hours. Stable in all benchies, like 3dmark06 and pcmark05. But, every once in a while after restarting for unknown reasons when I would go to start up Coretemp, or Everest to monitor temps it would lock those programs and refuse to load them. Granted that was also on 1.2 Bios on the k9a2 plat, so any gain from being at 2.7 was wiped out by the TLB fix. Rolled back to 1.13 to get away from TLB fix, and ended up having to knock the OC down to 2.5 at 1.25v for full stability.

Someone on Toms hardware has a theory that part of the Phenom's issue is a possible hotspot in the die, revolving around either the Northbridge or L3 cache. I do believe that the individual core readings that coretemp shows are correct. Under full load at 2.7 my cores were staying below 31c, but CPU temp according to everest was running and staying below 40c full load on all 4 cores.. So that temp difference between the cores and CPU has to be coming from somewhere.

phenom does NOT have individual core temp capability, ty i know... one diode for the entire package

[KTE]

phenom does NOT have individual core temp capability, ty i know... one diode for the entire package

It has 14 temp probes actually but for some reason, only one beneath the IHS and one internal core is gauged by software. That's why all Phenom core temps are always in sync.

[Rammsteiner]

Yep, it can increase oc/stability. Just have a high MaxAsyncLatency value and you should be good. If drive strength is incorrect, the system should tell you at bootup when it performs the calculations.

Already tried high MAL but well, about 10ns. That booted up fine however stability was a complete other thing not showing its face.

Well, the DFI BIOS at least has all those Drive Strength options like in the AOD. I saw a post of ozzimark somewhere (as he had the 4x 1GB record in the DDR2 database for AMD). He used some sort of program to change Drive Strength however Ive no clue what the calculations are behind those settings.

And how would the system tell me at boot up if calculations are incorrect? post codes? Like I got to reset my CMOS? Or more as Im about to start Windows, detecting IDE drives etc? Is there anywhere some sort of guide for it?

And as I said, I heard D9 can get killed pretty fast when Drive Strength is way too high/strong, so Ive really no clue but I'd like to learn about it. The fact I got it to run 293Mhz and do 1M SuperPI calculations and a few Everest tests tell me it's somehow possible to keep that speed, but I'd like to keep the V's a little bit reasonable though.

Also, as far as I understood, Drive Strength etc doesnt decrease performance but is like PCI-e clocks right? It can increase stability but if the frequency is too high/wrong it can kill the cards/DIMMs in it?

[Rammsteiner]

Ok, I tried setting Drive Strength to weak mode and the 3 strengths of 1.50x to 1.0x. Posted however didnt go beyond 'FF'. Set the changed strengths to 1.25x instead and it booted and ran 32M SuperPI with 2.3V . DIMM's weren't very hot, warm though, I guess about 30~40C. Gonna play some more later on but Drive Strengths are awesome obviously.

Just tried 2.25V but that wasn't doing it, got the SQR error in SuperPI. However maybe a little more Drive Strength tweaking will solve it. At least I know one of the changed settings doesnt like to be at 1.0x. So Ill trial and error wise try to find the one(s). Also the original 1.0x Ill try to start at 0.75x.

Less Voltage and less Drive Strengths seem to be a sweet spot, at least for D9GMH. Voltage isnt much of a problem for me though, more worried about Drive Strengths as they can kill D9's if they're way too tight.

FYI, Ive a 80CFM 92mm fan pointed towards the DIMM's from ~10cm and an unknown CFM 120mm fan 10cm above the DIMM's sucking hot air out of the case. So Ill try and get better results.

I dont feel like changing the Ohm settings though as that seems a little bit dangerous.

AFAIK lowering Drive Strengths doesnt hurt performance, not sure about it really. Does anyone know?

[Brother Esau]

No actually in some instances it increases it due to the way the memory interact s and the the way the data is transmitted to the Memory controller in the cpu.

It also could be that Transend Memory does not completely play well with DFI Motherboards that just may be the case as DFI Boards are very picky with Memory!

[Rammsteiner]

No actually in some instances it increases it due to the way the memory interact s and the the way the data is transmitted to the Memory controller in the cpu.

You mean the Drive Strength or the performance? Cause increasing the Drive Strength is the thing Im just trying not to do. If it's about performance, yeah. Certain lower timings dont automatically translate to better performance. When I had the A64 3400+ Clawhammer with OCZ PC3700EB I remember tRAS lower than 10 and higher than 10 gave worse performance than tRAS of 10.

It also could be that Transend Memory does not completely play well with DFI Motherboards that just may be the case as DFI Boards are very picky with Memory!

Haha, yeah, DFI is quite picky, especially combined with AMD CPU's. But with some tweaking things gets less worse

Im now running back at 2.3V again and set all Strengths to 1.0x apart from one, was set to 1.25x (can't remember which one anymore though) however it looks like I picked the right one as it booted up. Will post later on which one I changed.

However, Im thinking right if I set all those settings lower the Drive Strength becomes lower too right? I mean, it looks like a multiplier so lower multiplier would give lower... yeah lower... wtf Ive no clue.

Maybe Drive Strength is more about the Ampere trough the slots? Higher Volt with same Ampere gives more Watt which might be the thing killing D9's. If Ampere is lower Watt's will be reduced too. But Ive no clue on that. I just would like to know whether Im actually decreasing or increasing Drive Strengths the way Im changing things now. At least I set the DRAM Drivers Weak Mode to Weak, that's for sure weak then

[prostoman]

Ok, I tried setting Drive Strength to weak mode and the 3 strengths of 1.50x to 1.0x. Posted however didnt go beyond 'FF'. Set the changed strengths to 1.25x instead and it booted and ran 32M SuperPI with 2.3V . DIMM's weren't very hot, warm though, I guess about 30~40C. Gonna play some more later on but Drive Strengths are awesome obviously.

Just tried 2.25V but that wasn't doing it, got the SQR error in SuperPI. However maybe a little more Drive Strength tweaking will solve it. At least I know one of the changed settings doesnt like to be at 1.0x. So Ill trial and error wise try to find the one(s). Also the original 1.0x Ill try to start at 0.75x.

Less Voltage and less Drive Strengths seem to be a sweet spot, at least for D9GMH. Voltage isnt much of a problem for me though, more worried about Drive Strengths as they can kill D9's if they're way too tight.

FYI, Ive a 80CFM 92mm fan pointed towards the DIMM's from ~10cm and an unknown CFM 120mm fan 10cm above the DIMM's sucking hot air out of the case. So Ill try and get better results.

I dont feel like changing the Ohm settings though as that seems a little bit dangerous.

AFAIK lowering Drive Strengths doesnt hurt performance, not sure about it really. Does anyone know?

Not sure if this will help anyone, but my experience from playing with Drive strenghts on my Lanparty nf590SLi board, was that by changing the Drive Strength values, my memory was more stable overclocked further in MHz but worse timings, or that my memory would be more stable with tight timings, but much lower overcklock in MHz (same Voltage). Long time since I played with those values, so I dont remember exactly what made the difference for what.

I hope somebody got the point