jkelly1219,

If you have ram in there of different speeds, the PC will clock down to the slower ram sticks speeds.

Thanks for the response.  I am only putting one (1) stick of RAM in each PC and not combing different speeds. 

Yes, same result.  I have even tried using different RAM sticks (with higher speeds) on both PC's and still have the same result...  TXs

Have you reflashed the bios to the latest revisions?

Yes I did that for both PC's.  2400 BIOS is A05 and 4600 BIOS is A12.  That didn't help either.  I am a retired PC Tech and this has me lost....

TXs

Speaking directly for the 2400, I am guessing you have a Celeron processor. If that is the case, it will use PC2100 (266). That machine will only use PC2700 (333) with a Pentium processor. Since DDR is backward compatible, it should work fine, but will run at the speed it can use - 266 in your case.

I would guess there is a similar issue with the 4600, as they are machines from the same era. The Tech Specs for that machine lists two processor types, one at 800 Mhz and one at 533 Mhz, and it also lists two memory speeds, either the 333 or 400 you mentioned. I would bet you have the slower processor, and it uses the slower memory. Again, since DDR is backward compatible, it should work fine, but will run at the speed it can use...

Hope this makes sense and helps.

Dear Hrova, Thanks for jumping in...  I verified the 2400 has the Celeron CPU so that is probably the issue with that.  The 4600 has the 2.8 cpu / 533 bus / 512 cache (L2).  I have another 4600 with the 2.8 cpu / 533 bus / but has 1M L2.  Can the L2 cache limit the speed of RAM?  Again TXs to all

I own a 2400 so felt I could speak to that better. The 4600 was just speculation...

Perhaps a Dell moderator or other user can answer.... But my gut is saying there is a connection there.....

Thanks for the feedback.  There ain't no telling what the issue is, but you are probably in the right area.  Guess i will live with the issue until I find an answer.  Again thanks for you ideas 

.

MUTO, Thanks for the response.  It is informative in that I didn't think to put the cpu from the 4600 into the 2400.  I will have to research and see if it will fit.  However, I think you misunderstood my question.   See if I can clarify a bit....

The 2400 with the 2.4 Celeron (400 fsb, 128kb L2 cache) cpu is running single stick 400 MHz RAM at 266MHz

The 4600 with the 2.8 Intel (533 fsb, 512kb L2 cache) cpu is running single stick 400 MHz RAM at 333MHz.  

I have several 4600's in the house with one other having the 2.8 Intel (533 fsb) cpu.  The only difference is the other cpu has '1MB L2 cache'.  That 4600 runs the same single stick of RAM at 400 MHz.  So I guess the question is "Does the size of the CPU L2 cache make a difference on RAM Speed?"  I would have to say it must because between the two PC's everything is the same except the CPU L2 cache.  The motherboard, BIOS version, and all hardware is the same....   Your guess is as good as mine.  Anyway, thanks again for the suggestion to swap the cpu from the 4600 to the 2400 and buy a new cpu for the 4600.

The 2400 only accepts processors running at 400 Mhz, so the processor from the 4600 would not work.

Dimension 2400 Technical Specifications here....

Hrova, again thanks for the response.  If you look at the like you sent me it indicates that if I put an INTELL cpu in the 2400 it would run a cpu at 533.  Thanks for sending the link

Sorry, my bad.

Switching processors as muto suggested may be worth it for you.