"Pentium 4 2.8ghz / 800mhz fsb / 512kb cache / windows xp / 4 memory slots that can be single or dual channel up to 4gb of pc3200 memory. I Have the following: 1gb and 512mb PC3200 memory sticks, also 256kb and 128kb PC2100 memory sticks.

1st Question: Should I use all memory 1.875gb which will slow the channel memory rate to 266ddr or use 1.5gb at 333ddr?

2nd Question: will I gain much from buying a 2nd 512 mb pc3200 memory stick (putting the 2 512mb sticks on one side and the 1gb stick on the other) and running in dual channel mode?

If you can answer either or both questions, I would greatly appreciate it.

Thank You, ETE

Dani AI

Generated

Nice back-and-forth between and — below is a concise, practical plan plus a few technical notes to help choose and test the best setup.

First, decide by measuring real memory pressure on that XP machine. Run your typical workload, open Task Manager (Performance tab) and watch Available memory and disk activity when switching apps. If Available rarely falls below ~150–300 MB and you do not see frequent hard page faults (excessive disk thrashing), the 1.5 GB kit running at the board's native speed will feel snappier than a larger kit forced to run at a lower clock. If you routinely push memory past 1.5 GB (heavy multitasking, image editing, VMs), extra capacity is worth more than the small speed loss.

Second, if budget allows, add a matching 512 MB module that uses the same DDR333 timing/voltage. That gives balanced capacity per channel and the cleanest way to get both higher capacity and full dual-channel bandwidth on boards that support pairing. Before buying, verify the motherboard manual for the correct slot population order to enable dual-channel and confirm the board supports unequal-module pairing modes.

Quick checklist to apply after any change:

  • Populate slots per the manual so channels are balanced.
  • In BIOS, confirm reported memory speed and timings.
  • Run a few hours of Memtest86+ (or boot into normal use) to verify stability.
  • Repeat the quick workload test from step one and compare responsiveness and paging.

Summary recommendation: if you can afford the extra 512 MB of the same type/timings, do that for the best all-round result. If not, keep the faster matched modules and only increase capacity if you hit real memory limits during normal use.

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the 2 chips need to of equal size to work in dual mode ,and motherboard and cpu that supports it ,you definitely don't want to throw the 2100 into the mix, even in single channel mode.and the 2 512 and the 1 gig will not work together in ddr mode ,from what iv'e read on the site linked anyway more info here.

the 2 chips need to of equal size to work in dual mode ,and motherboard and cpu that supports it ,you definitely don't want to throw the 2100 into the mix, even in single channel mode.and the 2 512 and the 1 gig will not work together in ddr mode ,from what iv'e read on the site linked anyway more info here.

Caperjack - Actually your reply is worth a lot more tha "My 2 Cents".

I still need some help, you have helped me clarify my situation / dilemma!

Your statement about motherboard and CPU that supports it made me go back and take a second look...system only supports a maximum of 333MHz pc2700, the pc3200 installed is running in pc2700 compatibility mode and the article was also very helpful.

From what you have said, I'm ready to scrap both pc2100's (256k and 128k), if I run in single channel mode and use the 1.5gb in pc2700 mode. Did I understand that to be your advice?
Please look at the attached article from Intel, that is why I thought I could mix 1gb on one side and 2 512kb on the other side to achieve dual channel mode...Am I Missing something?

Thanks so much for your valuable insight, ETE.

now im confused ,but it look like according to the link that you can achieve dual Chanel with 3 chips ,i thought from what all i have been reading about dual channel lately that there had to be equal size chips in 2 matching channels ,but they show using 2 matching chips in the 2 matching channels and 1 unmatched size chip in a single channel by itself.any as you have no 2 chips that match in size they it looks like you are stuck using the single mode .

Thanks to Caperjack for great help! (daniweb would not let me add to your reputation today). sounds like you believe that I should run single thread at 333MHz with 1.5gb and not single thread at 266MHz with 1.875gb or buy another 512kb pc2700 333MHz stick and run dual channel (1GB stick on 1 channel and the matching 512gb sticks on the other...Is that waht is best?

something like that ,try it both ways see if you see any difference

Thanks

Thanks

your welcome

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