Memory

[greiner3]

I recently bought HP's d4999t Pavilion with the q6700 processor. They advertised it came with 2 Gb 800MHz pc-6400 DDR2 RAM. I also purchased 2 2Gb sticks of the same from Crucial. So the other day I downloaded CPU-Z and much to my surprise I find that I'm running all the sticks at 400MHz. I take out the 2 sticks of included (Hyundai) memory and then I do the same to the Crucial memory but in all three scenarios CPU-Z ;says that I am running only at 400MHz. I benchmarked via SANDRA and all the marks were very high, except for the ones that include memory. One other item about CPU-Z; it lists my memory as, '6144 MB PC2-5300!' I looked into this site's information about overclocking, however, this is a proprietary ASUS board and there are no such controls for me to change in the BIOS. Anyone have any suggestions? I wrote HP support yesterday and they said that if one module is running at 400 MHz they all will. Yes, I did know that and that is why I checked the memory in sections. I wrote back and am waiting for a response.
PS; I have 70-098 and A+ certifications so I sort of do not know what I'm talking about, at least sometimes.
I was going to invest another $80 and get two more 2Gb Crucial sticks. But if I can't figure this out, that would be a big waste of money.

 

[pinaplex]

cpu-z is correct, you're memory is running a 400Mhz x 2. That's where the DDR2-800 specification comes from. it doesn't mean the memory is actually running at 800mhz, it means it's running at 400mhz, but data is being transferred twice for every clock cycle. Hence the difference between DDR-400, and DDR2-800, both run at 400mhz.

 

[greiner3]

Thanks. I was not quite losing sleep over it but it was causing me anxiety. Maybe I should go back and get recertified. Mine was right before Win2000 came out.

 

[greiner3]

Since i started this thread and found out the answer, I want to know if there is a reason why my memory benchmarks so low. Is it the Hyundai memory? I guess I could take it out and run SANDRA on just the Corsairs and see if it was the reason.

 

[monst0r]

cpu-z is correct, you're memory is running a 400Mhz x 2. That's where the DDR2-800 specification comes from. it doesn't mean the memory is actually running at 800mhz, it means it's running at 400mhz, but data is being transferred twice for every clock cycle. Hence the difference between DDR-400, and DDR2-800, both run at 400mhz.

Thats not right. ANY DDR (Double Data Rate) RAM will transfer information on the rise and fall of the clock, hence the 2x system base clock. SD-RAM will run equal to the system's base clock. You should always run memory @ a 1:1 ratio with the FSB, no point in running it higher or lower (unless it wont clock that high..) If you can, set your RAM to run at 333 (667 effective) MHz in BIOS.

 

[monst0r]

Since i started this thread and found out the answer, I want to know if there is a reason why my memory benchmarks so low. Is it the Hyundai memory? I guess I could take it out and run SANDRA on just the Corsairs and see if it was the reason.

What do you mean by "low"? What are you comparing it to. Also, what are your timings, tightening them will give you more performance (not noticable really, about <5%) You shouldn't worry about synthetic benchmarks that much.