Ram 800 changed to 667 after 4gb upgrade

[ericsd]

After adding 2 more 1gb (pc6400 800 ) dimms my frequency changed to 667. I now have 4gb of ram running at 667, bios use to show 2gb 800 frequency. Does anyone know the answer to my problem?

[uddarts]

i'm guessing amd cpu and that's normal. you can try to manually set the fsb.

be sure to run memory86.


http://www.memtest.org/



ud

[BWM]

uddarts is correct. Speed fallback with increasing numbers of sticks is completely normal, does not indicate a problem, is per AMD's own published specs, and is not a AMD only characteristic.

[ericsd]

I called Dell, and they answered because the Dell ram latency 5 5 5 12 doesn't match with the new ram 6 6 6 12 latency.

[uddarts]

the 5-5-5-12 mem should be able to run 6-6-6-12. the above reference to 4 sticks and amd memory controller still applies.


ud

[ericsd]

I spoke to the ram seller and this is what they wrote: The Timings are basically the reason why the RAM has “shifted” to the DDR2-667 Speed. When you mix pairs that have different timings, the BIOS handles adjusting the timings based on the SPD tables. When the Timings are different, the BIOS shifts down to a Common Denominator. The common denominator in this example is 667, since DDR2-800 RAM is backwards compatible speed wise with 667,533,400, etc...

I decided to return the ram for matching latency, when I get the results I reply.

[ericsd]

And...The RAM that you Ordered (has "looser" timings then the Factory Dell installed RAM. When mixing Modules that have different Factory Set speeds in the SPD Table of the RAM, the Bios will "Auto Adjust" the Modules to a Lower Speed (667) to better match the Modules for Compatibility

So, in order for you to retain 800mhz DDR2 speeds, you would need to purchase RAM with the Same Timings in order to ensure compatibility at 800mhz

[uddarts]

ud

[BWM]

And...The RAM that you Ordered (has "looser" timings then the Factory Dell installed RAM. When mixing Modules that have different Factory Set speeds in the SPD Table of the RAM, the Bios will "Auto Adjust" the Modules to a Lower Speed (667) to better match the Modules for Compatibility

So, in order for you to retain 800mhz DDR2 speeds, you would need to purchase RAM with the Same Timings in order to ensure compatibility at 800mhz

It is still unlikely that 4 sticks will run at DDR800 even at 2T, but they just might. Here is AMD's memory config table for AM2.

[Mr_Speedy]

So it is unlikely that 4 sticks of RAM in an AMD system will run at 800MHz ?
Can they be manually set to higher?
I might get 4 sticks of 1066Mhz Kingmax Mars RAM. Will they revert back to 667Mhz? I would probably be better off with 2 x 1GB, and run them at high speeds....

[BWM]

So it is unlikely that 4 sticks of RAM in an AMD system will run at 800MHz ?

Yes. It is a normal property of any memory controller to drop back in speed with increasing amounts of memory, mainly when using more than two sticks. This is due to increqasing load on the memory controller and this is not just for AMD based systems.

Can they be manually set to higher?

You can try it, of course, but there is no guarantee that it will work.

I might get 4 sticks of 1066Mhz Kingmax Mars RAM. Will they revert back to 667Mhz?

Very likely.

I would probably be better off with 2 x 1GB, and run them at high speeds....

Yes, that is a better approach. Memory speed fallback isn't that big of a deal though because adding memory reduces paging to disk. Memory at any speed is still a heck of a lot faster than any hard drive.

[Mr_Speedy]

Thanks for the info

I also forgot about the 2 x 2GB option (DDR2-800), which is more expensive, but also a possibility.

If you can get a refund and sell your other RAM, 2 x 2GB might be the way to go ericsd.

[Prototype24]

Sorry to be rude and jump in here but I had a similar question.
I've got a K9A board with 2GB OCZ DDR2 PC2-6400 (OCZ2P800R22GK) and I'm running Vista 32-bit, now I know this only goes up to 3GB but I wanted to get another 2GB pack (OCZ2P800R22GK) as their very cheap right now.

My current config has the 2GB at 800Mhz Dual Channel 4-4-4-15, if I add the extra 2GB would this affect the these settings in anyway ie locked at 667Mhz?

[BWM]

My current config has the 2GB at 800Mhz Dual Channel 4-4-4-15, if I add the extra 2GB would this affect the these settings in anyway ie locked at 667Mhz?

Yes, it probably will wind up at 667 (and 2T as well). You might be able to get it back up to 800 but that isn't normal operation and to expect 800 with 4 sticks isn't advisable.

[alex666]

Sorry to be rude and jump in here but I had a similar question.
I've got a K9A board with 2GB OCZ DDR2 PC2-6400 (OCZ2P800R22GK) and I'm running Vista 32-bit, now I know this only goes up to 3GB but I wanted to get another 2GB pack (OCZ2P800R22GK) as their very cheap right now.

My current config has the 2GB at 800Mhz Dual Channel 4-4-4-15, if I add the extra 2GB would this affect the these settings in anyway ie locked at 667Mhz?

If that's an AMD board, I guess it will. If it's Intel, it won't, as I've had 4 X 1 gig of 6400 in my Vista32
ds3 system and it still ran at ddr2 6400. I did have to scale back my timings, however, to get all 4 dimms to work unless I really cranked up the volts, and I was very uncomfortable with doing so as there was lots of heat and the 4 dimms were rather tightly packed. I ultimately chose to pull those extra 2 dimms (now using them in a new system) as, all things considered, I saw very limited gain.

As for the question at hand, this reminds me of using ddr 400 memory in my soltek mobo (see sig). I installed 4 X 512 ddr 400 dimms and they actually ran at ddr 400 but only at default settings, and at 2T. However, as soon as I tried overclocking, even just a little bit, they bumped back down to ddr 333. I don't know if you would obtain similar findings with ddr2, but I thought I'd pass this on.

marty