Memory Speed With a7n8x

[andrewsilverman]

I just bought the following:
-Athlon XP 2600
-ASUS a7n8x motherboard with 400 MHZ FSB
-512 MB of DDR 400 memory

The bios is the latest and all the CMOS settings are at the default.

The system reports the memory speed at 200 MHZ at startup.

Any suggestions?

Thanks!
Andrew

[Ryanoffski]

I have the same problem. I was gonna post a thread, then saw yours. Here's my specs

A7N8X w/ 333mhz FSB
Athlon 1800
128mb & 256mb pc2100 ddr

memory frequency is at 166 mhz

[andrewsilverman]

I wonder if the memory speed is twice what is listed? (Since it's Double Data Rate)?

[VHockey86]

I think what its showing is just the DRAM speed, which is normally the same as your motherboard's FSB (half the processor FSB and half the speed of the memory)

[andrewsilverman]

Motherboard FSB and Processor FSB are not the same?

[VHockey86]

Well for example with my processor, its an amd xp 2000+, which has a 266mhz FSB, but the motherboard only runs at 133mhz. The "barton" cores run at 333 and 400, and thus have 166 and 200 mhz motherboard fsb

[Xtreeme]

No they arent. The cpu has its own fsb and the mem its own. DDR400 IS 200mhz Dram. Its double data rate mem. Which means x2. So 200mhz x2 =400mhz. The pc sepc is the mem bandwidth it can give. So pc3200 (ddr400) is good for 3200mb of bandwidth. thats why Duel Channel Double Data Rate Synchronis Dynamic Memeory pc3200 is good for 6.4gig of bandwidth. See why we say SDR and DDR and DCDDR instead.... Though athlon wont use more than 2.7gig effectivly anyhow with its small 10 stage pipeline.. Rest is overkill-small 3% gain is all.

[Xtreeme]

"I have the same problem. I was gonna post a thread, then saw yours. Here's my specs

A7N8X w/ 333mhz FSB
Athlon 1800
128mb & 256mb pc2100 ddr

memory frequency is at 166 mhz"

Ah you need asynch mode. go to bios-then where you set cpu aprameters up. Go to the mem heading and where it says 100% fsb choose 83%. THat will make the mem run within its spec again.

[andrewsilverman]

Does something like that apply to me as well? Or is 200 Mhz what I should expect to see for 400 Mhz memory?

Why does lower that percentage increase the speed?

(Sorry, if I'm ignorant, I'm just a software guy.)

[VHockey86]

PC2100 RAM is DDR266 and and will work as its designed to running at 133mhz fsb. I guess I've never used that motherboard but I was under the impression that the DRAM could not run slower than the FSB?. And unless hes overclocking an 1800+, it should be running at 133mhz ne ways (which is the right speed for DDR266 (pc2100)