Memory issue?

DaveGTY

DaveGTY

DaveGTY

Associate
Joined
22 Jan 2010
Posts
43
Location
Crawley
Hi everyone,

I added this question onto another thread, i don't know if it was missed or if it even is an issue so i thought i'd start a new thread in the hope that someone can help.

I was running 3d mark 06 and noticed on the results that my memory was shown as running at 400 MHz and i think it should be 800 MHz.

I used CPUZ and it shows the DRAM Frequency as 401.8 MHz. I then went to my BIOS and chose MB Intelligent Tweaker, DRAM configuration and the memory is shown as 4 x 800MHz. There is an option to set memory clock to manual but as it says 800 MHz on auto and i don't really know what i'm doing i haven't changed anything. I rebooted and CPUZ still shows 401.8 MHz?

Are 3d mark/CPUZ showing the memory as 400 MHz because it's double data rate? Is there something i should change in the BIOS? As you can tell i don't know much about it.

My system specs are:
MB - Gigabyte MA-790X-UD3P with BIOS F7b
CPU - Phenom 965 125w
RAM - 4x2 GB OCZ Gold DDR2 PC6400 800MHz
PSU - OCZ ModXStream Pro 600w

Sorry to post the same question twice :)
 
Your memory is DDR(v2) or Double Data Rate. This means that the actual clockspeed is only 400MHz (as shown in CPU-Z), but the effective clock speed is 800MHz. This is because data is transferred during both the rising and falling edges of each clock cycle.

Hence your memory is running at the correct speed - just make sure that the voltage and timings are the ones specified by OCZ for that memory.
 
Just like to point out...

Theres quite a big difference between the frequency of something and it's data rate. Manufactureres bluntly put data transfer rates in MHz or something, which is incorrect.

Effective clock is 800MT/s (Mega Transfers Per Second)

Only clock speed is measured in MHz and generally for every pulse from the clock cycle, as previously said, 2 transfers (in your case) take place.
There can sometimes be 4 transfers per clock cycle also which intel calls 'Quad Pumping' in which case your DRAM clock would be at 200MHz and data transfer rate at 800MT/s

My DRAM Frequency is currently is at 236MHz and something like 922MT/s...
Just thought this would help you out...

This may also help you out; see here
 
Agreed about the data rate, I said a MHz as that is what the manufacturers say - so it wouldn't confuse the OP, but you are quite correct that technically MHz is not accurate.

As for quad pumping, isn't that more to do with the FSB data transfer rate than the memory bus transfers. If it was memory then they would be calling it QDR or something :)
 
Ok, i've checked on the OCZ website and my memory should be running at 5-5-5-18 at 1.8v. I looked through my BIOS and it's actually set at 6-6-6-18 at 1.952v, this must have been default as i've fitted the mobo and memory myself and never changed anything. Should i change the timings/voltage?

Thanks to you both for the info. I only play games really and don't normally get involved with anything technical so sorry if it's a stupid question.
 
Ah, in that case I would change it to the rated settings as you are currently over-volting the RAM and changing to the tighter timing will provide a small performance boost.
 
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