My RAM is showing up as DDR200 instead of DDR400

[fredweston]

First, I'll give my system config in case it is applicable.

ASUS A8N-SLI Deluxe
2 x 512MB Mushkin PC3200 3-3-3-8
2 x 512MB Crucial PC3200 2-2-2-6
Athlon 64 4000+ San Diego
eVGA 7900GT Signature Series

This system originally had only the Mushkin memory, and then about a month ago I bought the Crucial to bring it up to 2GB. Both brands were purchased from NewEgg as 1GB (2x512) kits.

When I installed the Crucial memory, the BIOS reported the memory speed as 200 MHz. If I install either pair of the matching DIMMs alone, it reports 400 MHz as it should.

I thought that maybe the problem was because the timings were different, so I manually set my BIOS for the slower timings (3-3-3-8-2T) but it wouldn't POST. It's my understanding that CAS 2 memory should be able to run fine at CAS 3 for compatibility with slower memory, but it doesn't seem to be working out this way.

The computer runs okay with 2GB running at 200 MHz, but it seems slower than it did with only 1GB at 400 MHz. About the only thing that seems to run faster is BF2, I guess because it really benefits from the extra capacity?

In summary, I'm trying to figure out how I can use all four 512MB DIMMs at 400 MHz. It seems that there must be a way to accomplish this. I posted at AnandTech weeks ago and nobody there was able to give me any useful info.

Hopefully you can.

 

[b_diddy_t]

First thing before trying anything else is updating your bios. Then reset the default bios configuration (whatever your bios calls it).

Once thats all done, run memtest86, it should tell you up the top somewhere what speed it reckons things are running at.

Then run CPU-Z in windows and see what it says...

Then post back results.

 

[fredweston]

When I run memtest, should I just let the BIOS automatically detect the timings? In other words, will memtest still be able to see that things should be 400 MHz even though the BIOS has them running at 200 MHz?

I'll give this a shot tomorrow, as I won't have a chance until then. Thanks for the suggestion!

 

[sailer]

The different timings and brands of the ram are causing a conflict and then the computer is defaulting to a slower speed. You may be able to resolve this in the bios, but that may also cause a complete crash. The best route would be to either buy two more of the Crucial sticks or forget the idea of using four sticks of ram completely and get two 1 gig sticks. By the way, running four sticks of 512 will be slower than two sticks of 1 gig. Maybe you can make an exchange on the Crucial ram, or get your money back and use that money toward buying two 1 gig sticks.

 

[RichPLS]

also might try swapping the RAM banks to see if this makes them work together better...

 

[angry_ducky]

also might try swapping the RAM banks to see if this makes them work together better...

Basically, try putting the Mushkin sticks in the black slots, and the Crucial sticks in the blue slots. It might not work if you try to do dual-channel with two different brands of RAM. Also, check what the BIOS is setting the memory timings at.

 

[Heyyou27]

Hence the term "Double Data Rate" Or is your memory actually at 100MHz(200MHz effective) ?

 

[fredweston]

Here's what CPU-Z had to say. As you can see the memory is at 100 MHz (gag!) I'll give memtest a shot later today when I have more time. EDIT: Btw, this is with all BIOS settings on auto, as that's the only way I've been able to get anything to work thus far.

 

[fredweston]

Also, I just checked Asus's site and I already have the latest 1016 BIOS. There is a newer beta, but the word beta makes me uneasy.

 

[fredweston]

I ran memtest, but I didn't see any info about memory speeds? If they really are listed, could someone clarify where I can find them? I also tried moving the memory around in the slots, but it didn't seem to help. Any other ideas?

 

[Heyyou27]

Very strange; try running only half of your memory and see if it runs at 200MHz(400MHz effective). Can you manually adjust the memory speed? If so set it to PC3200/DDR400 and put your latencies to the latencies of the slower memory.

 

[fredweston]

Very strange; try running only half of your memory and see if it runs at 200MHz(400MHz effective). Can you manually adjust the memory speed? If so set it to PC3200/DDR400 and put your latencies to the latencies of the slower memory.

Running either half of the memory alone yields 400 MHz as I mentioned. As I also mentioned, setting it to 400 MHz manually in the BIOS with the timings set to the slower memory yields no POST. Thanks for trying to help though

 

[prolfe]

Previously you have stated that using either the Mushkin OR the Corsair separately works fine; I think you should try to identify the source of the problem by using just one stick of Corsair and one stick of Mushkin. If it still has the same problems (reduced speed or no POST) then the problem lies with either brand incompatibility or timing incompatibility. If, however, it runs well, then you have confirmed that the problem lies in using all 4 slots at the same time. Hope this helps!

 

[RichPLS]

very good suggestion... I concur.

 

[fredweston]

Indeed, that makes a whole lot of sense, and I feel kind of like an idiot for not thinking to try that. 2 kudos to you, sir! I'll give it a shot and see how it works.