Mixing Different Sizes of Memory Modules

Thanks...What got me thinking is that in the choices when building the machine the 3 gig choice is the only one that omits the words 'Dual Channel' (see below). So, if you select the 3 gig choice below you will still have Dual Channel?

 

1GB Dual Channel DDR2 SDRAM 667MHz - 2DIMMs 

1 GB Dual Channel DDR2 SDRAM 800MHz - 2DIMMs 

2GB Dual Channel DDR2 SDRAM 800MHz - 2DIMMs 

3GB DDR2 SDRAM 800MHZ - 2X1GB+2X512MB 

4GB Dual Channel DDR2 SDRAM 800MHz - 4DIMMs 

There is no problem.  There is no issue with dual channel as long as each size is a matched pair.

 

Peter

Thanks again...hopefully Dell will install them correctly.

One of my "advisors" mentioned that there could be an issue with the timing being different between the 512 and 1 gig modules. Does that mean anything to you guys?

what will happen if the timings are differnt is that the system will run the ram at the lowest speed and loosest timings. so if you had mem at say 5-5-5-25 and were to add some at say 5-5-51-15, all the ram would run at 5-5-5-25. So in essences you would be paying for better ram but not being able to fully realize it. Same would hold true if one were to mix the memory speeds. Like for example adding 400mhz ram in a system with 333 mhz ram. the whole ram would run a 333mhz, so again you would be paying for 400mhz ram but it is not running like it should. While this is not a big deal it can be just a slight waste of money buying better ram but not really utilizing it fully.

If the new mem and old mem are the same speed and only slightly differnt in timings then there will be no issues.

 

 

Well, the suspense is over. Computer arrived. This is how the RAM is set up and what it says:

DIMM 1: 1 GB 1Rx8 PC2 - 6400U - 666 - 12
             HYMP 112U64CP8 - 56 AB - C 0825
             HYNIX Korea

DIMM 2: 512 MB 1Rx8 DDR2 - 800Mhz - CL6
             PC2 - 6400U 666 - 12 - DO
             V916764K24QCFW - G6
             0819 - M3575080
             ProMOS Malaysia

DIMM 3: Same as DIMM 1

DIMM 4: Same as DIMM 2

Any interpretations?
Thanks.

3 gigs of ram. Slots  #1 and 3 are paired as is slots # 2 and 4. Memory is dual channel which means it needs to be installed in pairs to acheive the best performance. This is a very common arrangement for ram modules.

Your set up if perfectly fine. :smileyvery-happy:

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@Davet50 wrote:

3 gigs of ram. Slots  #1 and 3 are paired as is slots # 2 and 4. Memory is dual channel which means it needs to be installed in pairs to acheive the best performance. This is a very common arrangement for ram modules.

Your set up if perfectly fine. :smileyvery-happy:

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Thanks..I'm sure everything is fine.  Can the timing be ascertained from the info I posted or no?

 

no. but if you pick up a free program called CPU-z it will report your memory timings. you can get it HERE