PC 133 SDRAM Memory

I need help selecting SDRAM memory for my HP Pavilion Model 7955 which uses PC 133 SDRAM. I currently have 512MB (two 256MB sticks which occupy 2 of my 3 DIMM memory slots). I’d like to increase this memory to 1GB (that’s the max for my computer) and I need advice. I note that PC133 SDRAM memory comes in different types, like CL 2 or 3, unbuffered (and I suppose buffered?), non-parity (and parity?), ECC (or not), etc. I need advice on exactly what I need to look for and purchase. By the way, HP will charge me to talk to them about this and they’ll still be winging it (my own experience). So, I think you guys can help me much better. Do I need to be concerned about putting new memory in any particular slot? Would a third 256MB stick help that much (giving me 768MB)? Would it be worth the effort/money or should I just go for the 1GB? To save money, should I go with two 512MB sticks or would one 1GB stick function better than two 256MB sticks? Is the Cas Latency that important? Is CL=2 better than CL=3, if so why? Any help or comments would be most appreciative. If I forgot about anything important, let me know…I need advice before I go shopping. Thanks guys.

There are numerous web sites (MicronPC) being one of them, where you just enter in your pc model, and it will tell you exactly what memory you need. You want what ever memory you buy to closely match what you have. If you currently have cl3 memory, and buy cl2, your cl2 will only run as fast as the cl3 that is there. (CL2 is faster than CL3 if you are comparing the same speeds ie: pc133). Or, open up your pc, and pull one of your memory modules and get all the information right off the chips. Then buy comparable memory. You will notice some difference with 768mb, and won’t really gain much by going to 1gb, unless you are using photoshop, or encoding video. You can go to wikopedia and find out what ecc and buffered memory is for.


PC133 is outdated, so if you get modules, they often are crappy and incompatible. The risk of getting such low quality memory increases with module size.
Also, PC133 is getting expensive unless you buy used modules from ebay or so.

And there is another thing to think about: You would have to replace both existing modules by larger ones. Many mainboards refuse to work properly with three memory modules inserted although they are equipped with 3 DIMM slots.

So, I’d recommend to stick with the memory you already have and save the money in order to buy a new system at a later time.


Crucial scanned my computer and told me what I need. And I am involved with video capturing and editing and burning DVD’s…hopefully. Was trying to make the process run a bit better…but as Michael said, it’s probably not worth the BIG $ to upgrade such memory. Crucial wants $95+tax for one 512MB stick…and x 2 = $200 is way too much to waste on memory alone.

So, unless I can find some very inexpensive, but good, PC133 SDRAM memory, I’m going to forget about the memory upgrade. I want to build my next computer someday anyway.

I wouldn’t spend any money on this system, I would save and build a new computer. :iagree:

That is the problem with a form of memory that is being phased out, it goes up in price like no mans business as production is wound down. Therefore I would go with DJ on the recommendation to save up.

Looked it up on Crucial…

CL2 or CL3 (if all modules are CL2, it should use the faster CL2 timing), unbuffered, non-parity, and NO special compatibility warning.

Mixing RAM can be problematic, though often a problem with particular motherboards.

Using all 3 slots might work, and I’d be tempted to load the 3rd slot with another 256 for 768 total - 50% more, purely because the 256 module is a much more friendly price.

And with no special compatibility note, you should be able to shop somewhere that is not a “memory specialist”.

Crucial: MT16LSDT3264AG-13EB1


Crucial: MT16LSDT3264AG-13EE3

Both 256, synch, 133 CL2

One has MT# CT32M64S4D7E-16T
other has MT# Ct32M64S4D7E-16LT

If either of these is of interest to you, PM me. If you’re in the USA you can have them for shipping.

You could get a new motherboard that supports beter ram and a gig of ram and use your old cpu, for not much more than the cost of a 512MB chip.

Great approach ripit…what Mobo and what type ram would you recommend?

Will most mobo’s fit in my HP Pavilion model 7955 mini tower?

Unfortunatlly, I am not that farmiliar with intels (been running amd for a long time). I can help you with some info though and perhaps someone with more knoledge of intels can fill in the gap. From what I can tell from a quick search, pentium 3 cpu’s use socket 370, which only suppports sdram. Lets wait for someone more farmiliar with intel to verify that though. Along the same lines of a new motherboard, consider this.
Amd sempron 2400 (socket a) 72$ (ripoff)

socket a motherboard
cheapest on newegg 34.79$

a good brand motherboard 59.99$

1 gig ram (2x512), it wasn’t worth listing the cheapest as it was not that much cheaper
good corsiar ram 69.99 http://www.newegg.com/Product/Product.asp?Item=N82E16820145440
Total is 180-210$ (roughlly)
You get a newer, beter quality motherboard, a much faster processor, and 1 gig of much faster (corsair pc3200 valueselect) ram.

I just quicklly picked stuff off newegg for example price, so do not take those as recomended parts. I just listed them to give you a ball park figure of price. It might very well be worth spending a few more dollars to go socket 754 or 939.
There are two kinds of motherboards that most systems use. They are atx and microatx. The only thing I found on your system so fat was uatx? You need to check into that (more info on your exact model of computer might help me find it). The above motherboards are atx. I also don’t know if you have a video card or onboard video. newegg lists 12 microatx motherboards with onboard video (no vid card required) for between 35-60$ for socket a so that doesn’t change price much. Fyi the onbard video is probably much beter than what is on your pentium 3 so you get an upgrade there too.

First thing, find if your motherboard is microatx, atx or other.
Second, find out if your power supply is at or atx (if it is at, it will have 2 6 wire conectors that go to the motherboard, if it is atx, it will have on conector with 20 wires).

My personal opinion, you are seriouslly throwing your money away if you pay mega inflated prices for obsolete equipment like sdram (unless you can find some used cheap). There are factors to consider though. Is your power supply atx, and if so, is it powerfull enough to handle the new equipment? Will my copy of windows xp work on the new motherboard or is it locked to the old computers motherboard?
I started with a piece of crap celeron computer 5-6 years ago, upgraded piece by piece (couldn’t afford a good computer all at once), and I think it is the way to go (unless you can afford it all at once). You could actually build a system using some of your exsisting parts pretty cheap (win xp and a monitor are two of the bigest costs, but you have a monitor and might have windows xp). For that matter there are bare bones systems quite cheap too (doesn’t include several things you already have so don’t need). Custom gets you much beter equipment than prebuilt systems though.
If it is workable (have to check out you equipment more), to get a motherboard, cpu and memory, for the same price of 1gig of sdram, you have made major upgrades. for a little more money (socket 754 or 939), your upgrade can become even more substantial. Also, these new parts continue to be of use if you further upgrade your computer.
Any thoughts on that? Also, please tel us as muchs as possible about your current equipment (be detailed). Perhaps we can try to figeure how much of it is usable for now.

Try Powerleap.com. You might be able to just upgrade the CPU on your motherboard for about $150. That might justify the cost of increasing your SDRAM.


[font=Tahoma]I hope you can read the info below (hold down and run your cursor over the area where the text should be…like after Manufacturer, after Model, after Chipset Vendor, etc. this worked for me…don’t know what caused this and I couldn’t correct it):[/font]

Manufacturer : ASUSTeK Computer INC.
Model : P4B-LA Rev.
REV 1.xx
CPU Slot/Socket Type : mPGA-478
Chipset Vendor : Intel i845 Rev.[color=white] A3
Bios Manufacturer :[/color][color=white] Award Software, Inc.
Bios Version : 3.05[/color]
My power supply is "200 watt Bestec model ATX-1956D", definitely needs upgraded.

By the way, my windows xp home edition came pre-loaded on this HP Pavilion model 7955. I have no xp disk…but I do have 7 system restore disks that HP finally sent me.

If you change the motherboard, you are likely to void the OEM Windows XP - Microsoft have tightened up activation, so it is no longer possible to activate BIOS-Locked OEM versions.

It appears to be the codename “Amazon” Motherboard… see:

Info: http://h10025.www1.hp.com/ewfrf/wc/genericDocument?docname=bph07293&dlc=en&lc=en&cc=uk

A BIOS update to 3.11 is available

I don’t know where I got the idea that your computer was pentium 3? It is a socket 478 pentium 4 and you should be able to find a good quality motherboard that can take that cpu and ddr ram for a decent price. As you can defanatlly use your current cpu, you are looking at 120$ (maybe less depending on the motherboard) for 1 gig of corsair value ram (2x512) and a motherboard.
Unfortunatlly it looks like your motherboard is uatx. These are even smaller than microatx and were designed for use in very small compact computers. It limits your choices quite a bit but there do seem to be some like this one.
I’m really not that farmiliar with uatx (I use full size tower cases with full size atx motherboard though I do have an old celeron computer that is microatx), but some computer cases have mounting for more than one kind of motherboard (the larger ones can usally take the smaller size boards too). Maybe if you are lucky, the case can fit a microatx board in which case there are many options for motherboards. Hp’s site kind of sucks but I’ll keep looking and see if I can find anything about your case (unless someone else knows and can post). If nothing else, I can find you the specs for the diffrent sizes, and you can check out your motherboard tray to see what mounting it has. You could always take it to a computer shop and ask them what size motherboards you can fit too (act like you want to buy one from them, then after you find out tell them you want to think about it). I would think that some shops might do it for free (and you never know, they may actually have a motherboard you like for a decent price).
In the mean time, can anyone else confirm that this is a uatx motherboard?
It lists it as uATX -> ATX whatever that means and it looks like a uatx board?

Also, a warning, like Matth said, if you change your motherboard, your crappy oem copy of windows may not work (i have seen some oem versions work after a motherboard change but many do not). Also, if your computer is under warranty, changing stuff yourself might void it. If your luck is like mine, your copy of xp wont work, but you can get a motherboard, 1 gig of ram, and a full retail version of windows xp (oem which doesn’t have tech support but is a full, unrestricted version is 80-100$). For around the 200$ that the sdram would have cost. You also get a full copy of windows out of it (that will always work on any computer you get no mater what the hardware).

First of all, can he change the motherboard? I thought all these manufacturers like Dell, HP, Compaq, Gateway, etc. have proprietary mobos made by Intel or another manufacturer by contract to fit their specially designed mini-tower cases.

Burnselk, have you checked powerleap.com at all to see if a simple CPU replacement might help? They have great kits that include the heatsink, fan, etc.

Take a look at the results for your system:


They’re saying that this CPU upgrade matches your system for $220:
Intel P4 2.8GHz 400MHz FSB 478pin 512K Northwood CPU OEM
400 MHz Front Side Bus

Here you could get it for $187 with the heatsink and fan:


If you search around, you might find it for a lower price. If your Pavillion is the P4 with the 1.5 ghz chip, this is a decent upgrade. It will keep your machine going for another few years. Once again, you could get a decent AMD Athlon emachine for about $600 AR with an LCD monitor, so it’s your choice.

At this point, I would probably upgrade and eventually buy or build a second machine. I’ve found that if one machine crashes, I’m lost, and a 2nd unit would come in handy to search the web for tech info and drivers if necessary.

[QUOTE=WiltonParmenter]Burnselk, have you checked powerleap.com at all to see if a simple CPU replacement might help? They have great kits that include the heatsink, fan, etc. QUOTE]

I thought of that too Wilton and wanted to explore going that route but during an on-line chat with an HP tech, I was told I could go no higher than 1.6GHz on the cpu upgrade for this particular model. Wish I could, who’s right powerleap.com or HP?

[QUOTE=ripit]If nothing else, I can find you the specs for the diffrent sizes, and you can check out your motherboard tray to see what mounting it has. /QUOTE]

ripit, I appreciate your help on this.

If HP has a discussion forum on their site, I would post the question there.
You can also e-mail Powerleap. They’re pretty good at responding.

You also might want to register for the Tom’s Hardware Forums. They people over there are wild over their computers and you might get some good opinions on not only the CPU upgrade but the motherboard and SDRAM, too.


I cannot find dimentions on the uatx boards anywhere. I’ll look a little further though. In the mean time, you can compare the hole locations and board size of yours to these (under layout)

I did read somewhere that a flex atx board may fit in a uatx system, though it was on a forum so I would want some confirmation on that one.

Just found this. Someone on the hp forums said that uatx is the same as microatx. If that is true, then there are lots of motherboards that will work (check your dimentions against the microatx dimentions I gave above though).