Question on CPU speed vs RAM
 

Hi folks,

I have a question on speed of CPU vs RAM size

I am going to build a workstation running Gentoo 14 or its later version. My major target on the new WS is it won't take too long time to compile, install, etc. source packages downloaded from Gentoo website. I am sitting on 3MB broadband. My former planning is to have AMD 2.5/2.6G CUP and 1G DDR400 RAM. Can I achieve a better performance by reducing the RAM size to 512MB DDR333 and with the cost thus saved to upgrade AMD CUP to 2.6G+?

Kindly advise.

TIA

B.R.
satimis

keep the ddr400, you wont see much different in speed with the faster CPU. if im not mistaken the memory bus and the system bus run seperatley now so even if the bus on your CPU is less that 400 yoru memory still runs at 400.

Hi,

Thanks for your advice.

Can you please explain in more detail on

"memory bus and the system bus run seperatley now so even if the bus on your CPU is less that 400 yoru memory still runs at 400"

TIA

B.R.
satimis

I don't believe you can increase your memory bus speed to more than 200% your FSB speed (the default). At least my BIOS won't let me. The DDR400 would definitely be nice though if your CPU is designed for a 200MHz FSB (which requires DDR400) or if you plan on overclocking.

The system and memory bus speeds are still the same. DDR RAM just uses both the the rising and falling edge of the wave which effectively Doubles the Data Rate (DDR). So DDR400 still works at 200MHz but they cram twice as much data in there as older technologies.

A lot of BIOSes at least let you set your memory speed to something lower than your FSB, but I'm not sure about higher. Mine lets me choose in increments of 10% up to 200% of my FSB speed.

BTW, here's a pretty good webpage with a definition for you. It also has a link to a webpage that talks about system performance: http://www.ddrmemoryram.com/

Hi,

It is an interesting link. Thanks.

Additional question, have you tried AMD CPU delivered on bulb (tray) package before? I have been using AMD CPU for several years without problem but only box package. The physical difference which I can recognize between them is one with box and heat sink+cooling fan another without. What are the differnece between quality and warrantee.

B.R.
satimis

My suggestion: Both the mobo and the CPU will have a rating for the FSB. You want those to match. Similarly, the FSB will determine what kind of RAM you should get. The point is that you want everything to operate at the same speed.

One example: Take a AMD Athlon "Barton" 2500+ chip. It's got an FSB of 333Mz, and runs fast. You might want to pair this with an Asus A7N8X mobo, which supports the 333 FSB. If you go with both of these choices, then a good RAM choice would be Kingston DDR333 (PC2700) RAM, again because the speed matches. Where you run into trouble is with systems where one component operates faster/slower than the others. -- J.W.

If you're building an SMP machine (multiple CPUs) buying them out of the same tray/lot ensures stepping numbers will be identical; which can sometimes be the cause of intermittent and seemingly mysterious problems. For a single CPU machine you get a better warranty with the boxed processors. You also get a quality fan. Nothing more annoying than a computer that sounds like a jet airplane taking off. :o The price difference isn't enough to justify the hassle IMHO. Unless you're planning on overclocking it, I suppose. In which case you can spend more on cooling than the CPU. Was just looking at a case with built-in radiator for water cooling... some people really like to go nuts with their PCs ;) Check it out: http://cgi.ebay.com/ws/eBayISAPI.dll...tem=3451494221