|"Originally I had 2 x 512 of PC2700 8 chip and 16 chip in slots 1 and 3 IBM and Kingston respectively. With 2 x 512 KVR400X64C25/512 (16 chip) in 2 and 4. Everything in single channel."|
Dual channel mode is mostly hype. In the real world, all else being equal, most people can't perceive the difference between the two modes - it's at most a very small percentage.
All the installed modules have to support dual channel mode in order for any of them to run in dual channel mode.
I'm assuming you installed the modules in the proper spots to support dual channel mode.
The modules that were in slots 1 and 3 probably cannot support dual channel mode because they are not identical - even if other specs were the same, they have different numbers of chips, and probably different memory densities on the individual chips.
If they - 1 and 3 - weren't running in dual channel mode, then all 4 modules cannot run in dual channel mode, even if the other two - 2 and 4 - do when installed by themselves. If you had removed the modules in slots 1 and 3 and left the other two in, if those two are in the proper slots to support it, they should run in dual channel mode in that situation.
On the other hand, as I pointed out above, Kingston does NOT list ANY Intel brand mboard, which is probably what you have, as supporting using KVR400X64C25/512, but they DO list KVR400X64C3A/512 as being supported.
The KVR400X64C25/512 16 chip modules probably need to be forced to use a CAS of 3 rather than 2.5 on your mboard, at 400mhz.
"The new KVR400X64C25/512's (8 chip) don't work at all. Not even one 512 by itself."
You hadn't mentioned that you already had them.
OK, then, there's some about them that's incompatible with your main chipset, but it probably isn't specifically just the number of chips, it's something else.
Obviously, SOME 512mb modules with 8 chips work - your PC2700 IBM module does.
The Kingston KTM-M50/512 modules should work for sure, since they are specified for your IBM model, despite them probably having 8 chips, according to what pictures of them I found (see above).
Since the KVR400X64C3A/512 modules were originally specified to have 16 chips too, they may not work either, if you can't find any that have 16 chips.
KVR400X64C25/512's (16 chip) worked @ 2 3 3 7 in dual mode only @ 166.2 MHZ (??)
Any reason why the PC3200 runs @ PC2700?
It appears you must set the CAS to 3 or more on this mboard for ram to run at 400mhz.
- It says here:
"Systems with 800MHz FSB processors should use the KTM-M50/xxx (DDR400) part numbers.
Systems with 400 or 533MHz FSB processors should use the KTM8854/xxx (DDR333) part numbers."
If you have a 400 or 533MHz FSB processor, the fsb runs at 333mhz, and maybe the ram can't run faster than that, in that situation,
OR, you may need to set the 400mhz ram speed manually in the bios Setup, because the bios defaults to setting it to 333mhz, which is sometimes the case.
For some chipsets if you populate all the ram slots, all the ram runs at 333mhz max despite the fact fewer modules will all run at 400mhz max (I have an Asus A7V600 mboard that has that situation).
NOTE that all the ram you have installed must support 400mhz in order for any of it to run at 400mhz - if you mix 333mhzand 400mhz modules, all of it will run at 333mhz.
NOTE that it appears the mboard chipset supports ram with a CAS of 3 (or a higher number) at 400mhz, NOT 2.5. If the bios settings allow you to set that lower than 3, the module is forced to run at 333mhz
"The only reason I bought the KVR400X64C25/512 is because the price was like $18 a piece and I thought they were 16 chip"
Ram of a particular size and speed with fewer chips is usually much cheaper than the same with more chips.
Rarely, some sites that sell ram specify the number of chips on the modules.
If you want to find ram with 16 chips, which may not be necessary, try searching using something such as "16 chips" DDR 400 512
However, the module you get has should be listed somewhere as being compatible - e.g. KVR400X64C3A/512 is.
I used "16 chips" KVR400X64C3A/512 and found some "hits", e.g.
Kingston ValueRam 512MB DDR-400 Unbuffered 184-pin DIMM (Picture is for illustration purposes only)
Part No: KVR400X64C3A/512
(California; also have web sites in Aus and NZ)
Other sizes with 16 chips:
Or you could get other brand name ram other than Kingston ram that is listed for your IBM or Intel mboard model.
Or you could get generic ram that is guaranteed to work in your model.
E.g. MemoryGiant, but they don't list 400mhz modules.
"The motherboard only says IBM with no model and the chipset is intel i865P/PE/G/i848P according to CPU-Z"
Like most brand name system builders, IBM doesn't make the mboards in it's desktop systems, but it may have IBM specified markings on the mboard. Usually, mboards in IBM desktop systems were made by Intel. Info I found says your model has the Intel 865G chipset. In theory there should be a D865G or D865Gxxxx model number where x are 1or more extra letters, either printed on the mboard somewhere, or on a stuck on label on the mboard. If you don't see that, there should be an IBM part number for the mboard, probably on a stuck on label that also has a bar code on it - that may be useful to look up which mboard it has.