PC ram desktop

uhh…need help on updating my ram.

i have a compaq presario, athlon 750. originally came with a PC100 256 DiMM(?) or SIMM(?) i dunno. i then bought another PC100 256.

now i would like to buy a 512 one to replace one of the 256. but am having trouble finding the same kind. the DDR ram slots (pins) look different. mine has three bunches of pins (2 long, 1 short). will anything else work? can i just buy any PC133, 400, etc that looks like it would fit. or do i have to make sure from compaq the motherboard can handle it? what kinds of prices am i looking at. saw fnac (for convenience) had 512 DDR for 100USD. but will prob end up going to guanghua. just don’t feel like getting ripped off. hope i am making sense.

I don’t know where you are, but I found the guys at 3C at the corner of Roosevelt and Heping to be very helpful and honest when building my current PC. I don’t think their RAM prices are too bad - I paid NT$2,700 for 512Mb of DDR333 RAM last month. I don’t know what kind of RAM your machine would need, and I have heard it said that Compaqs require proprietary RAM. However, in the past I have had no problem sticking PC133 RAM in generic PC100 machines.

You should first check whether your MB/chipset will support more than 512mb of RAM. Open the case and check the chipset number and MB maker, then do a web search. I made the mistake of buying an extra 256MB on top of the 512 installed, for my Asus MB, luckily the guys at Aurora on Keelung Rd exchanged it with no hassle.

The easiest way is to go to crucial.com and use their RAM locator to figure out what kind of RAM you need. Then going out and buying it. They also have info on how much each slot will support (usually)

If you currently have PC100 RAM then you cannot use DDR memory. The slots, motherboard and chipset are not designed for its use.
You need to buy some more PC100, PC 133 or PC 150, the latter two being backwards compatible with your, probable, 100MHz system memory bus.
One of the previous posters is right, your chipset (not motherboard) may limit how much RAM you can install. Also the motherboard may be fussy as to how many sides of RAM are loaded with memory modules. My board can only hold 5 sides of modules (ASUS) Computors from two years ago were not intended to hold as much RAM as today’s systems.
If you can give me your MB details ie Manufacturer, model and chipset then I can look it up for you.
To find details (on XP) Start>All Programs>Accessories>system tools>system information>the left column should display ‘System summary’ In the right column look under ‘BIOS Verson/Date’. Tell me what is written there.
I have too much time on my hands.

xp tells me it’s phoenix techlogies ltd 7/31/2000

i have a compaq 7000 7AP135 (athlon 750)
crucial tells me to use pc 100 or 133 sdram max mem is 512 (for 2 slots) and each slot max seems to be 256.
went to guanghua, seemed no one had pc100. but then i screwed up and bought the wrong pc sdram. will exchange it for 2 pieces of 256 pc133.
but they only have CL=3 and crucial says only CL=2. is this a big diff?

Haven’t you answered your own question here? You’ve already got 512mb in there…and the max you can use is 512mb, why are you buying more??

I didn’t notice this earlier but…512MB isn’t enough for you? Wow…what are you doing?

In any case, CL2 and CL3 are the cycle length times (lower numbers are better). But realistically, unless you’re into overclocking or showing off your benchmarks, I haven’t noticed a real-world difference.

Yes, your questions are answered, 512Mb is your max. You can probably run more but your system will be so unstable as to make it a headache.
It is the opinion that two 256Mb sticks of RAM are better than one 512Mb and CL2 and CL3 doesnt make much real world difference.

Also, you have to be doing video editing or photoshoping in order to need more than 512Mb and in any case if you were, then your processer would be seriously slowing you down as graphics manipulation is heavy on the processer.

The only upgrade choice you really have to make is new motherboard processor and RAM. I dont consider a need to upgrade worthwhile and I have 900Mhz and 512Mb. It’s enough for me to play DVDs a few games and plenty of surfing. Waste your money in a good bar instead.

If I could recommend a minor upgrade I would buy a USB v2.0 card. It improves camera, scanner etc data tranfers and only cost about 800

thanks for the advice.
just to clarify. currently i have 2 sticks of 128 for a total of 256. (came with original compaq 128 stick)
the max allowable appears to be 512. I was just considering keeping 1 128 stick and upgrading with a 256 for a total of 384. since i can’t find pc100 sticks, and i am told i can’t mix and match diff bus speeds, i thought i would just get 512 (2 sticks of 256).
went to guanghua, bought 1 512 (it was cheaper than 2 256), but didn’t work, so now i am going back and exchanging for 2 256)
no i don’t need a lot of memory, 512 should be fine. i think my bottleneck is graphics card. right now i have a 8mb nvidia. and with some games there seems to be too much virtual memory being used (I assume this is a hardware accel. prob. thus fixable with a better vid card) and winxp just reboots (or crashes, then reboots)
i dont need a better processor, nor would i want to bother spending extra money for that.
anyways my next purchase would be a laptop, so saving up for that