How important is the power supply when adding sdram ?

Star

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May 22, 2004
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I have a computer that I got in 2001 with 512 mb of sdram, speed pc 133. My computer's motherboard has three dimm slots. I would like to upgrade the ram on this computer and according to my computer's specifications it looks like it will allow me to put three 512 mb chips in each of the dimm slots for a total of 1.5 gigs. Right now the computer only has two 256 meg slots in two of the dimms.

My question is: Is the amount of ram I can add dependent on how much wattage my power supply has ? For instance, if my power supply has 200 watts, would that be a factor in how much ram I can add or is it not a factor ? Thank you for any info you can offer !
 

Nightowl0707

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Since we're talking about a 200w PSU that may already be pushing its limits I'd at least check though. I've read that you should add 7 watts per 128mb of RAM and if that’s correct, the OP would be adding 70 watts (1280mb additional) to what's currently required. The calculator that I provided above only adds about 35 watts for 3 sticks of PC-133 SDRAM so I’m not sure how accurate the “7 watts per 128mb of RAM” rule is but even 30 watts could be too much of an additional drain on a 200 watt PSU.
 
But since he is already running 2 sticks, he is actually on adding 1 more stick which I see works out to about 11 watts. I think that 7 watts for every 128 meg is a little steep.
But, thanks for the link, that is a good thing to have handy.
 

Star

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Thank you for the replies :hello:

I was actually thinking of removing the two 256 meg chips that I already have in two of the slots and replacing them with a 512 meg chip in each slot. I was nervous about the power supply issue, though, because it is so low. Thank you to the posters in this thread for letting me know that the amount of ram is affected by the power supply, even if only to a minimal degree. :( Maybe I will just replace the two chips with one 512 meg chip while I look at that tool the above poster was helpful enough to link :) In the end, since the power supply does seem to be somewhat of an issue, I might just add another 512 meg chip later on for a total of 1gig of ram for this computer. Thirty five watts of power may not be much added, but the power supply unit is so low I can't help but feel it would make some sort of difference.
Thank you !
 

Mondoman

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Presumably HP designed your computer to handle the maximum 1.5GB of RAM. I wouldn't worry about the power supply with regard to the RAM; however, if the computer has been in constant use for the last 6 years, you shouldn't be surprised if components start failing. I'd be most worried about the hard drive, then perhaps the MB and power supply.
 

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