Memory Speeds Problems with CPU-Z

I seem to recall seeing a long time ago that when you populate all 4 slots with 4 sticks of DDR2 800 ram that it will downclock to 667 speeds, something to do with IMC (memory controller) limitations. Been looking around but can't find the reference at the moment.

You should be able to set it manually to 800 as Duzzy suggests above, but if you do get it there don't be surprised if it isn't stable. All things considering if things are stable with the ram at 667, I would just leave it there. That and as nice as it would be to get it running at its rated speed, unless all you run is memory benchmarks you likely won't even see a difference (1-2% maybe) with it at 800.

essenbe said:

Windows Memory Diagnostic test is not as comprehensive as Memtest86. Here is a tutorial on how to run memtest86. It will take several hours to run the test, it is best to do it overnight. In bios I always have temp warnings on and normally you set a target temp for the fans. That will make them speed up if the temp increases. And the fans should be running. Also, you should have a section in BIOS called Hardware monitor which will tell you voltages and temps. The main page is usually system information which tells you your CPU type and speed as well as your installed ram and the speed of the ram as well as other info. That page is normally for information purposes and does not allow for changes.

EDIT: Don't be concerned, many people are not familar with bios and don't go there often. It is quite common.

Hello,
Memtest now works!! Thanks. I also took a shot at the BIOS. Found where I could bump the ram speed to 800MHz. I now realize that on the POST screen it was showing DDR 667!!!! Well it now shows DDR 800. I ran the index assessement test and the times are exactly the same as with it set at DDR 667. So I went back and set it to auto. Unless I missed something, it seems the increase gave me no more perfomance benefit, by itself. You can comment on any obvious mistakes. CPU-Z also showed 401 as the DDR Speed when it was changed over.
Cool!
Glenn

Duzzy said:

I've attached two screenshots, the first being what you need to change to force 800Mhz (CPU-Z 400Mhz) and the second to change the two timings essenbe suggested (post #4).

Due to the mixed RAM you may have problems. The two SR2G sticks have 3 JEDEC's and a EPP the other two only have three JEDEC's and the timings and voltages are different. I'm pretty sure this is why your RAM is running at 333Mhz because under that profile the timings and voltages are closer to the same.

Now forcing the RAM to 800Mhz may cause a problem with the auto timings so you may need to manually set the timings as well.

I think we need some overclocker's to have a look if you really want it running at 800Mhz (400Mhz). I mean if it was me I would remove the two SR2G sticks and make sure there running at 800Mhz (require save and exit) before writing down the timings in the right hand column. Next I would set the speed back to auto if it needed to be changed and then put all 4 sticks back in and then set to 800Mhz. Next set the voltage to 2V, overvoltage on two sticks, and set the timings to what you wrote down. Then most importantly test with MemTest.

The timings would be safe for the two 2G sticks and the voltage would be sufficent to run the SR2G sticks at a CAS# Latency of 5. But I wouldn't know if the 2G sticks could handle 2V for long.

You could also test at 1.8 volts as it may be the 4,4,15 that requires the extra voltage.



But this is just me, not a experienced overclocker.

Thanks for your informative assistance. As I noted in the reply to essenbe, I only changed the timing to 800 GHz and didn't notice any change in the index performance, so I reset it. Do to my limited knowledge, I don't expect to see a remarkable increase on tweaking the values closer to correct. So unless an overclocker will come on and let me know of a valid reason, I set it back to auto.
Appreciate your time
Glenn

stormy13 said:

I seem to recall seeing a long time ago that when you populate all 4 slots with 4 sticks of DDR2 800 ram that it will downclock to 667 speeds, something to do with IMC (memory controller) limitations. Been looking around but can't find the reference at the moment.

You should be able to set it manually to 800 as Duzzy suggests above, but if you do get it there don't be surprised if it isn't stable. All things considering if things are stable with the ram at 667, I would just leave it there. That and as nice as it would be to get it running at its rated speed, unless all you run is memory benchmarks you likely won't even see a difference (1-2% maybe) with it at 800.

From my limited test, described above and the results I am in agreement. I set it back to auto. Better safe than sorry! Thanks stormy13!
Glenn

essenbe said:

I believe I said in a previous post that you would notice no increase in performance. But, the link I gave on memtest86 says to run I think 7 passes. 7 passes will take 8-10 hours to run. The frequency of the ram is really not noticeable except in benchmarks. I have run 1333, 1600, 1866 and 2133 MHz ram and can tell no performance difference in actual usage, only in benchmarks.

Yes Sir, that is why I changed it back. I ran memtest for a couple hours, didn't notice but it had a complete on it and it was running another. So I don't know how many passes it made. It sees it as DDR 667. Not a single error. Fingers crossed. Thanks essenbe, you have helped me understand and test. I feel much more relaxed {)!
So later I'll read about the test more and set it up to run all night. Do you trust those gadgets with the core temperatures on it?
This forum is great, and many thanks!
Glenn