Opteron 165 OC, memory divider issue

[Phaethar]

Hey all,

I recently jumped on the Opty 165 bandwagon with the hopes of hitting at least 2.7Ghz on it. Got a good stepping, and after a bit of burn in and testing, have found the CPU to be quite stable at 2.7Ghz at 1.375v.

The problem I am having is memory related. I have 4 sticks of DDR400 memory. Nothing special here, so I was going to try and keep it as close to stock speeds at possible. Running my HT multiplier at 300x9, I set the memory speed to DDR266, which clocks the memory at about 193Mhz. This means the memory should be slightly underclocked, but not really too noticeable. This is proving to be very unstable unfortunately. Thus far, the only way I've been able to get things stable with the CPU at this speed is to run the memory at DDR200, which effectively puts me at DDR300 speeds.

As I'm new to Athlon64 overclocking, I'm curious to know if this is a somewhat common thing, or if there is something I'm missing. As it's running slower than stock, I assume that messing with the DDR voltage wouldn't help. I wouldn't think easing up on the timings would help either, but of course I'll give it a shot if it might help.

Just looking for a bit of advice.

Thanks.

 

[haste]

with 4 sticks of ram you probably need to run at 2t timing.
give that a shot and see if it works...

 

[Phaethar]

Thanks for the tip on this, but I'm already running at 2T timing. Even at stock speeds for everything, I could never get all 4 sticks to run stable at 1T. Was absolutely stable for months at 2T though.

Edit. I'm at work right now, so I can't say exactly what timings I'm running. Other than changing the clock speed, the rest of the memory timings are set to auto. I know it's setting CAS to 2.5, and timing to 2T, but can't remember the rest off the top of my head. Would manually setting the timings a bit lower potentially help, even with a lower overall speed?

 

[CustomBuild]

Remember that the memory itself is only part of the equation. For AMD the memory controller is on the CPU. When you overclock the CPU you effect the memory controller also. Which is why timing can become so important. OC the CPU and using dividers can stress the controller and if its timings are slightly off you have to addjust for them. That plus your board (crosstalk etc.) all factor in.

My suggestion is search all the various boards in the overclocking databases and see what people have used for your exact memory. Or do a general search on 3-4 sites for you memory and see what people have to say. Often times it takes tweeking one of the secondary timings to get it in sync. You can do it your self but there are a lot of settings and it would be faster if you can find someone else with your memory (and preferably MB)that has already gone through it (likely).

Be as specific as you can when you search for your memory. You list Corsair DDR in your sig. You will have to be more spicific than that. In addition you list 1.5G. That means that all 4 sticks can't be the same which will make it more difficult because the timings each pair will like will be different. That will limit you significantly.

 

[Varmint]

I have a similar question - I can only hit 2.50 GHz on my 165, is it because I have to use dividers like DDR300 and DDR233?

I can hit 2.52 GHz using DDR333 divider (ram at 227 or something), but any higher at that divider and my memory can't handle it.

I could sell my OCZ for probably $180 and buy some G.Skill DDR500, then use 1:1 or 5:6 dividers, would that help my 165 get to 2.7GHz?

 

[IanG]

Have you tried bumping the voltage to your memory by 0.1 or 0.2 volts? Also try running with just two sticks and see if it makes a difference - you might be able to sell or trade your 4 sticks for 2 bigger ones if that works.

 

[krelkor]

I have a similar question - I can only hit 2.50 GHz on my 165, is it because I have to use dividers like DDR300 and DDR233?

I can hit 2.52 GHz using DDR333 divider (ram at 227 or something), but any higher at that divider and my memory can't handle it.

I could sell my OCZ for probably $180 and buy some G.Skill DDR500, then use 1:1 or 5:6 dividers, would that help my 165 get to 2.7GHz?

move down to a 266 or even 200 divider, cpu speed is king!

 

[Phaethar]

Be as specific as you can when you search for your memory. You list Corsair DDR in your sig. You will have to be more spicific than that. In addition you list 1.5G. That means that all 4 sticks can't be the same which will make it more difficult because the timings each pair will like will be different. That will limit you significantly.

Yeah, I set up most of the sig a long time ago and just never filled in the details. I'll grab models tonight when I get home, but it's all Corsair Value Select, and I believe has all the same timings. I'll check to make sure and see if I can find some other examples of dividers using the same memory, and it's pretty popular stuff if NewEgg is to be believed.

Have you tried bumping the voltage to your memory by 0.1 or 0.2 volts? Also try running with just two sticks and see if it makes a difference - you might be able to sell or trade your 4 sticks for 2 bigger ones if that works.

I did try upping the voltage in small increments, to no avail. Also, I know I'm pushing my luck with 4 sticks anyway, I was hoping that by running the memory at stock speeds I could keep it all working. It's worth a shot though to see if things run stable with only 2 sticks.

 

[Varmint]

move down to a 266 or even 200 divider, cpu speed is king!

I have tried those, it doesn't help. My understanding was the lower the divider the more unstable it makes the system? That 1:1 or 5:6 is best for trying to overclock higher?

 

[Phaethar]

move down to a 266 or even 200 divider, cpu speed is king!

Just out of curiosity, but how true is this? My memory just will not run at a 266 memory divider with the CPU HT set to 300x9. However, setting the memory to 200 works great.. giving me a FX-60 class processor with DDR300 speed memory.

Without running hours of benchmarks, am I better with the faster CPU speed and slower memory, or should I slow down the CPU (say HT 250x4), set the memory to 333 (which works great so far, slightly OC'd memory even) and have the CPU run at 2.2Ghz instead of 2.7?

Just curious what would give better overall results in general PC gaming.