DDR 400 with 333 FSB?

karel69 · 06-15-2005, 06:20 PM

i've just ordered a new mobo, cpu and ddr module over the internet. But i have a question: the ddr module i bought is a 400 MHz one, while the cpu is designed to run at a 333 MHz FSB speed. (Both of them are supported by the mobo of course.) but is it actually wise (or even possible) to get a system working with asynchronous fsb/ddr. Do i have to purchase a 333 MHz DDR module, or will i need to set the fsb to 200 MHz, increasing the multiplier (btw, is this even possible, considering that the socket A sempron is designed for 333 FSB)? Or can I just leave things the way they are? And if i do leave things the way they are, is it true that some performance goes to waste then due to the asynchronous fsb/ddr?

LittleHoov · 06-15-2005, 06:26 PM

i think the DDR400 will just run at 333 instead of 400, so yes i guess some performance would be lost.

NeuromancerWGDD'U · 06-15-2005, 06:36 PM

I'm not sure about the actual performance speed, but I have a similar setup; Athlon XP 2700+ (333 FSB) and 512 MB DDR400 (2x256). When I set the RAM control to "auto" in the BIOS, it loads the RAM as 166MHz dual-channeled, but when I set it to "by SPD" it loads up as 200MHz dual-channeled. The setup won't have any problems loading/running, but I don't know if the RAM is actually running at 200MHz, or if it's just telling me it is. I suspect the former.

dunerider5 · 06-16-2005, 04:32 AM

This came from the ram 101... I think you can trust praetors advice.

Budget Machine
Generally shoot for PC3200 (even if your board supports only PC2700). The reasoning is (a) running budget PC3200 on a PC2700 board may allow for tighter timings and thus a wee bit more performance, (b) the price delta is not significant between one or two speed grades and (c) PC3200 allows for a bit more upgrading.

So my guess is it will work...

**Praetor** · 06-16-2005, 07:49 AM

It'll definitely work and if the board supports having an asynchronous CPU/DRAM clock then you can have your CPU at 166MHz and the RAM at 200MHz. Reliastically there isnt a world of difference between the two both in terms of price or performance

karel69 · 06-16-2005, 05:47 PM

thanks, but will it actually make any difference whether i use 333 ddr or 400 drr?

alanuofm · 06-16-2005, 05:53 PM

like in praetor's advice. it will make a "wee" bit of increased performance. couldnt hurt anyways

06-15-2005, 06:20 PM	#1 (permalink)
karel69 New Member Join Date: Jun 2005 Posts: 4	DDR 400 with 333 FSB? i've just ordered a new mobo, cpu and ddr module over the internet. But i have a question: the ddr module i bought is a 400 MHz one, while the cpu is designed to run at a 333 MHz FSB speed. (Both of them are supported by the mobo of course.) but is it actually wise (or even possible) to get a system working with asynchronous fsb/ddr. Do i have to purchase a 333 MHz DDR module, or will i need to set the fsb to 200 MHz, increasing the multiplier (btw, is this even possible, considering that the socket A sempron is designed for 333 FSB)? Or can I just leave things the way they are? And if i do leave things the way they are, is it true that some performance goes to waste then due to the asynchronous fsb/ddr?

06-15-2005, 06:26 PM	#2 (permalink)
LittleHoov Gold Member Join Date: Mar 2005 Location: Climax Springs, Missouri Age: 21 Posts: 311	i think the DDR400 will just run at 333 instead of 400, so yes i guess some performance would be lost. __________________ ZTSystems Notebook Intel Core Duo 2 TS5450 1.66ghz 3GB DDR2 RAM 250GB Hard Drive Nvidia 8600M GT OCed at 600/430 plus a host of other goodies.

06-15-2005, 06:36 PM	#3 (permalink)
NeuromancerWGDD'U Gold Member Join Date: Apr 2005 Location: I miss Oregon... Age: 19 Posts: 477	I'm not sure about the actual performance speed, but I have a similar setup; Athlon XP 2700+ (333 FSB) and 512 MB DDR400 (2x256). When I set the RAM control to "auto" in the BIOS, it loads the RAM as 166MHz dual-channeled, but when I set it to "by SPD" it loads up as 200MHz dual-channeled. The setup won't have any problems loading/running, but I don't know if the RAM is actually running at 200MHz, or if it's just telling me it is. I suspect the former. __________________ My little machine: S423 Pentium 4 1.3Ghz, 4x256 16-bit RIMM RAM, 32MB TNT2 video card. I think it may be time to upgrade... The upgrade! My machine will soon be a 939 X2 4000+, 4x512 DDR400, and an 8600GTS.

06-16-2005, 07:49 AM	#5 (permalink)
Praetor Administrator Join Date: Jul 2004 Location: Canada Age: 25 Posts: 19,954	It'll definitely work and if the board supports having an asynchronous CPU/DRAM clock then you can have your CPU at 166MHz and the RAM at 200MHz. Reliastically there isnt a world of difference between the two both in terms of price or performance __________________ ASUS P5K Premium WiFi-AP, Q6600@3.7 / ASUS P5ND, E6400@3.8 4GB OCz Platinum XTC 8500 / 4GB CorsairXMS2 6400 5x500GB Seagate 7200.10 / 2x500 Seagate 7200.10 OCz 8800GTX 768MB @ 630/800 / 2x Galaxy 8800GT SLI

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06-16-2005, 04:32 AM	#4 (permalink)
dunerider5 Silver Member Join Date: May 2005 Posts: 117	This came from the ram 101... I think you can trust praetors advice. Budget Machine Generally shoot for PC3200 (even if your board supports only PC2700). The reasoning is (a) running budget PC3200 on a PC2700 board may allow for tighter timings and thus a wee bit more performance, (b) the price delta is not significant between one or two speed grades and (c) PC3200 allows for a bit more upgrading. So my guess is it will work...

06-16-2005, 05:47 PM	#6 (permalink)
karel69 New Member Join Date: Jun 2005 Posts: 4	thanks, but will it actually make any difference whether i use 333 ddr or 400 drr?

06-16-2005, 05:53 PM	#7 (permalink)
alanuofm Diamond Member Join Date: Jun 2005 Posts: 1,630	like in praetor's advice. it will make a "wee" bit of increased performance. couldnt hurt anyways