C2D E6700 with DDR2-667

[joeytang]

My company is looking to by me a new computer. Unfortunately I can't build my own and have to get a dell. I have spec'd out a new precision with a C2D E6700 with a 1066 FSB. However the RAM that dell sells is only DDR2-667. I have talked with our sales rep and he has assured me that the mother board they use will support the DDR2-1066 memory.


My question is will there be a noticeable performance hit if any running the PC at 667MHz FSB. I haven't been keeping up on processor and RAM for the past couple of years. In the past wouldn't even work. Should I spec the precision out with the minimum RAM and purchase the 1066 from another vendor?

 

[accord99]

Even with DDR2-667 memory, the E6700 will run at the correct 1066MHz FSB. There is a small performance benefit if you were to run DDR2-800 memory, it's typically only a few percent:

http://www.xbitlabs.com/articles/memory/display/core2duo-memory-guide_5.html

 

[joeytang]

Thanks for the reply. I guess not keeping up with processor and memory technologies has left a void in my knowledge.

 

[epsilon84]

Actually, DDR2-533 would be sufficient for running in sync with the 1066MHz FSB.

I know it's pretty confusing if you're not a techy, but basically the 1066MHz FSB is actually the result of a 'quad pumped' 266MHz FSB, while DDR stands for 'double data rate' so 4 x 266 for the FSB/ 2 x 533 for the RAM = 1066 for both, perfectly in sync.

Anyhow, there is only a small benefit from using faster RAM on the C2D platform. DDR2-1066 is only about 3 - 5% faster than DDR2-667 in real world performance.

http://anandtech.com/memory/showdoc.aspx?i=2800&p=7

 

[jackluo923]

Hopefully, dell's motherboard has dual channel memory controller. If the dell mobo support dual channel, then 533mhz ram will be 533mhz x2 thus equals 1066mhz (1:1 with the cpu's fsb and memory ). If the case being dell doesn't have dual channel memory, then you should spend some money on 800mhz memory and overclock it to 1066mhz since this method is a lot cheaper than getting 1066mhz memory.

 

[joeytang]

Thanks for the replys. I'm understanding this much clearer now!