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Upgrading RAM/ CPU

Dilan77 asked
Medium Priority
Last Modified: 2010-07-27
Hi there,

I'm not at all an expert on desktop hardware, so thought I'd throw this out to you guys...

We have several, fairly old, Compaq EN-series Deskpros here. CPU is about 500 Mhz and RAM is 125Mb. They have about 10 GB hard drives.

They're all running Windows XP, Office 2003 pretty slowly, although it is manageable.

We were contemplating throwing these away and getting new machines altogether, but I'd like to boost their power and save them.

 I guess I could add more RAM, but is there anything I could do to boost the CPU power? Is it possible to buy new CPU chips and, if so, how much do they normally cost (I'm in the UK)?

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Top Expert 2012

If these are PIII's, the maximum speed replacement cpu will depend on the form factor (slot1 or socket370), the ability to update the BIOS to recognize the new cpu, and the FSB the motherboard supports.  CPUs can be compared here: http://www.cpuscorecard.com/cpuprices/ip3.htm

Hi Dilan77,

Probably, to buy a new faster CPU, you'll need also buy new Motherboard, new RAM and a new Graphics Card. Check your motherboard's specifications if it can handle new processors keeping the RAM and Grphics Card. Probably it can't.
There's a chance that won't fit in your pc box, depending what you have and what you'll get.
Then, you'll have brand new box, new motherboard, new processor, new RAM and new Graphics... with an old slow HD... You'll need to buy a new. Maybe you'll need also a new power supply...
What remains? The floppy drive..., plus the external stuff (keyboard, mouse and screen). Is it worth?

Yes, you can upgrade the machines.  Adding 128MB of ram would be very cheap (under $50), and make  noticable difference.  A faster CPU is possible also, but more trouble to figure out which one, and you will also have to upgrade the BIOS.  That might net you up to 20% increase in apparent speed.

Dramatic speed increases are unlikely.
Going beyond simple ram upgrade, CPU upgrade, is not recommended.
eBay is your friend for obsolete computer upgrades.
A local computer store can help you identify the parts to buy.

HP has good upgrade guides, and recycling guides, online.  Knowing the exact model number helps.

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Top Expert 2012

> That might net you up to 20% increase in apparent speed.

I beg to differ - it depends on the motherboard, but in theory, PIII's go up to 1.4GHz, and 1.0Ghz may be a reachable goal.  WinXP will definitely benefit from 256MB or more of RAM.

Note the word "apparent".  If he upgrades a 500Mz CPu to 1.0Ghz, there is no way the machine will appear twice as fast (except in the simpliest of unrealistic benchmarks).  For a real application like M$Office, the apparent speed increase will always be much lower.

CPU upgrades should cost $40-$80, depending on the exact age. eBay is your friend.
Top Expert 2012

Point taken ;-)
I'm running some Dell P II 233-266 MHz with Win XP, the trick was to put at least 192 MB RAM, they're not fast but small spreadsheets and text editing works fine.

As for the CPU upgrade you need to be very careful about the voltage, I've got an Asus P2B wich is an Slot 1 MoBo, it can only take up to PIII @ 600 MHz but with NO leter attached to the name, a PIII @ 600 E won't work due voltage settings.
Q-Is there anything I could do to boost the CPU power?
    Is it possible to buy new CPU chips and, if so, how much do they normally cost (I'm in the UK)?

( for Compaq Deskpro Small Form Factor Pentium II generation socket 370)

good luck
Need more specific info about your system to make anything more than a guess.
The Deskpro EN-series has a long lineage and many different motherboards were used.

What the hell, I'm bored........

From what I can tell most of the EN-series 500MHz vintage machines were using an intel i810 chipset.

i810's came in several versions.
The i810e supported 66/100/133MHz CPU's but the earlier i810's only supported 66/100MHz CPU's.
Max memory is 2 slots with 256MB each. (512MB total.)

You may also have the slightly older BX chipset.
If so basically you can -probably- have more total memory but less processor speed.
The types of memory and processor options are similar but some BX boards can only go up to a certain CPU MHz and what that is varies. These use 66/100MHz CPUs and memory. BX chipsets support a max of 1GB memory but max-per-slot is 256Mb so if the board only has 3 slots them max is 768Mb for that board. http://www.intel.com/design/chipsets/440bx/

Some motherboard manufacturers extended the i810 or BX chipsets to use 133MHz CPU's by splitting the FSB.
The CPU's FSB is 133MHz but the board itself is still at 100MHz.
This is also the case with i810e chipsets.
The difference is on the i810e Intel approved it and on the earlier chipsets they didn't so it's "unofficially supported" on those motherboards that can do it.

i810/i810e should go to a 1GHz P3 CPU without any problems.
BX boards going over 800/850Mhz are rare. (Or non-existant.)

Slot 1 or socket 370 is still a question.
(Watch the FSB when you are shopping. They all came in 66/100/133MHz FSB.)

The socket 370 1GHz CPU's are cheap and common.
They are running $30-$40 on eBay. (I needed one last week.)

The slot 1 version P3 1GHz is rather hard to find and a bit more expensive. $45-$50(up).

A slightly slower CPU in either slot or socket will be much cheaper.
(Except 800-850MHz and up Slot 1 CPU's which are about what a 1GHz socket 370 runs. A market thing.)
Slot 1 700MHz-750MHz are fairly cheap now.
Socket 370's are often cheap up to 850-900MHz (sometimes even the 933MHz go cheap.)
- Pay attention to the FSB you need!!

You can use a 'slocket' to adapt a socket 370 CPU to a slot 1 board. It's fairly safe IF the board would support a slot 1 CPU of the same type as the socket 370 CPU. It can be taken further but success becomes more iffy. (As in converting a 133MHz CPU to run on a 100MHz board. - Sometimes it works with slockets but don't count on it.)

The memory you would need *MUST BE LOW DENSITY* and low density memory is more expensive.
If the ad doesn't -SAY- "low density", "for older systems", "universal compatibility" or something like that or if it says "for VIA Chipsets" or "for newer systems" then keep looking, that ain't it.

You need to determine if your system needs Buffered memory or ECC memory (Or worse yet that rare EDO that ended up on 168 pin modules. Unusual but it happens.) before you go buying memory.

The best way is to look up the existing module then get the same stuff.
If it's EDO I'd sell off the module and replace it with SDRAM.

The i810 chipsets do not support ECC or EDO but BX chipsets support ECC/non-ECC and SDRAM or EDO.

With SDRAM you'll need PC66, PC100, or PC133 depending on the FSB speed of your CPU/Mainboard.
- Don't buy PC66. It's a waste. PC100 or PC133 will work better anyway.
PC133 is prefered even if you have a 66/100MHz FSB. (This does not apply to many Laptops.)
Memory that is CL3 at 100/133MHz will normally run stable at CL2 on a 66MHz system.
Memory that is CL3 at 133MHz will normally run stable at CL2 on a 100MHz system.
When I need PC133 I hold out for PC133 with a cache latency of CL2.
(Real basic analogy: CL2 means the signal goes at every other clock pulse, CL3 means it goes every 3rd clock pulse.)

All this won't matter if your other (old) module is CL3 at the FSB speed used because the slowest module sets the pace for all the modules. You might consider getting a 256MB CL2 module and getting rid of the old 128MB module (if it's CL3.)

A 256 Mb Low Denisty module would normally have 16 chips. (Chip count on other sizes varies.)
256 Mb PC133 CL2 modules have been running $30 to $50 on eBay.

Note: Memory advertised as PC150 (or even PC166) is in reality the same as very fast PC133. - Some manufacturers were already building 'PC150' or 'PC166' when the industry shifted to DDR Memory instead.
It runs just dandy at CL2 on 133MHz. (KingMax PC150 is GOOD stuff!)

Nuther note: Steer clear of Kingston "Value RAM" for this one unless it specifically says it's for YOUR system. Meaning any Kingston module with a "VR" anywhere in the part number. Many of the Kingston "Value Ram"s of this vintage were built for very specific OEM systems and for some reason Kingston is secretive about the true specifications. (Density?/ECC?/Buffered?) They often show up as used 'pulls' but it's nearly impossible to tell what you are actually getting and compatibility problems are common. I'm not saying it's poor quality. (Though as "Value RAM" it might be.) I'm saying you can't tell what it IS by the part number.


For CPU Upgrade, take a look at Powerleap . . I have upgraded several Dell machines successfully . . although at todays prices for pc's it is becoming less and less of an economic move.


Powerleap is awesome equipment (high quailty, well built, NOT junk) but they are EXPENSIVE.

You can usually replace the mainboard, cpu, and memory for less than what a powerleap costs.
Heck, I just bought a 1.2GHz P3 Tualatin -SYSTEM- for less than a Powerleap cost to get to the same level.


Thanks everyone for the detailed help!!!

I think I'll go along with installing more RAM and seeing how that goes.

Good choice... more RAM.  When your machines run out of RAM, they 'pages' and 'swap' to the hard disk.  That's draatically slow.  So for running MS office, go with at least 256MB total memory, and preferably 384MB.  Much beyond that is unlikely to pay off on these older machines.  Using Tools->Disk Deframentor is also good, netting up to perhaps 5% speed increase.  The Microsoft 'Quick Launch' tool can speed the load time of MS Office, at the expense of slower boot time.
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