Hi,

In my experience the primary bottleneck for P4s were that their relatively small cache sizes makes them very reliant on the speed of the FSB to communicate with the system RAM, the Prescott Celeron D has the same amount of on-chip L2 cache as that 1.8Ghz Northwood and when the data is not in the cache it will have to go through the slow 400 MHz FSB to fetch data. For tight loops the Prescott Celeron D will make a speed improvement, but for most real world applications I don't think that it will be that noticeable.

The GPU upgrade is a significant one, but the GPU is already not the bottleneck in this system unless the load is extremely GPU heavy, so I would personally wouldn't bother with it.

If you have 1.8ghz/400/256 that's a Willamette core not a Northwood.

You would be better served by getting a 2.4 or 2.6 ghz 400FSB Northwood which has 512k of cache. Prescott doesn't have many architectural improvements that will help in games (it was often slightly slower clock for clock in benchmarks of the time), and the slow SDRAM will still be very limiting no matter what CPU you have.

You could also replace the motherboard with the later NetVista model 49P1605 which supports DDR and 533 FSB and performs much better.

onethirdxcubed wrote on 2026-05-28, 23:04:

If you have 1.8ghz/400/256 that's a Willamette core not a Northwood.

Thanks for correcting me on that, I haven't noticed that 256 is an invalid L2 Cache size for a Northwood.

For the OP: True Northwoods have a 512KB L2 Cache while Northwood core Celerons have 128KB L2 Cache, so as onethirdxcubed suggests the best upgrade that you can make while keeping that board is to get an actual true 400 MHz FSB Northwood.

onethirdxcubed wrote on 2026-05-28, 23:04:

If you have 1.8ghz/400/256 that's a Willamette core not a Northwood.

You would be better served by getting a 2.4 or 2.6 ghz 400FSB Northwood which has 512k of cache. Prescott doesn't have many architectural improvements that will help in games (it was often slightly slower clock for clock in benchmarks of the time), and the slow SDRAM will still be very limiting no matter what CPU you have.

You could also replace the motherboard with the later NetVista model 49P1605 which supports DDR and 533 FSB and performs much better.

I took a Via chipset 400 MHz motherboard with a Celeron and replaced it with a 2.8 533 P4 and the difference in performance was pretty dramatic. It had slots for both SDR and DDR and it came with SDRAM, so with DDR and the faster CPU and greater memory bandwidth it was like a different computer.

That is if it works at all, if the motherboard doesn't know or like the Prescott it might even not POST.

I think probably the best you can do for that board is a 2.4/400 Northwood.

Vanilla 845 won't work with Prescott. The upgrade path is pre-HT Northwood clocked at 2.4-2.6 GHz. But overall SDRAM P4s are not worth upgrading. It should be performing about the same as PIII 1GHz Coppermine system already.

First of all, thanks everyone for the advice. I only found a 2.0 512KB 400MHz P4 at a reasonable price in my country. Should I buy it? By the way, the point of this upgrade is to keep as many original parts as possible.

And I forgot to give a link to that mod: https://web.archive.org/web/20070709003537/ht … tt/prescott.htm

"
I adapted a Celeron-D 330 (2666) processor using your method. It seemed to work, but the result wasn't perfect—details on the forum: http://rom.by/phpBB2/viewtopic.php?t=8260
After several attempts, I found the following solution:
I insulated the AD1 (BOOT SELECT) pin with heat shrink tubing;
DO NOT insulate the AE26 (OPTIMIZET/COMTAT#) pin, otherwise there will be problems with automatic voltage adjustment;
AB22 (TESTHI7) and AA20 (TESTHI6) pins don't need to be touched, as they should already be connected to the power supply via 56 ohms;
Pins AF3 (VCCVIDLB) and AD2 (VIDPWRGD) should be connected with a jumper to AF4 (VCCVID), not to VCC (it's recommended to connect AD2 (VIDPWRGD) via a 680 ohm resistor).
(Possible side effects: the 1.2 volt voltage regulator for VCCVID on older boards may not be rated for this load—Intel says the current increases from 30 to 150 milliamps).
After the modification described above, everything seems to be working as expected—the voltage is set correctly, and there are no issues with processor initialization.
"

There are some photos of my setup. The following will be installed into the holes: DDS2 HP DAT Streamer, Colorado 130MB streamer, and Magneto-optical Fujitsu drive.

It's possibly a trick of the light, but in your second photo it appears that there are several capacitors that are failing; if so, the board will need to have the capacitors replaced.

The Serpent Rider wrote on 2026-05-29, 09:10:

Vanilla 845 won't work with Prescott. The upgrade path is pre-HT Northwood clocked at 2.4-2.6 GHz. But overall SDRAM P4s are not worth upgrading. It should be performing about the same as PIII 1GHz Coppermine system already.

Considering there were “pc166” sdram, I always wondered why the P4 was the odd duck that had zero overclocking support.

I also found it strange they didn’t bother allowing the ram to be interleaved. With 4 slots a 4 way interleave could allow for a psuedo 400mhz clock with lots of latency outside pipelined operations

Repo Man11 wrote on 2026-05-29, 12:57:

It's possibly a trick of the light, but in your second photo it appears that there are several capacitors that are failing; if so, the board will need to have the capacitors replaced.

Yeah, I know. I wil definetely do it, but a bit later.

MagefromAntares wrote on 2026-05-28, 23:28:

onethirdxcubed wrote on 2026-05-28, 23:04:

If you have 1.8ghz/400/256 that's a Willamette core not a Northwood.

Thanks for correcting me on that, I haven't noticed that 256 is an invalid L2 Cache size for a Northwood.

For the OP: True Northwoods have a 512KB L2 Cache while Northwood core Celerons have 128KB L2 Cache, so as onethirdxcubed suggests the best upgrade that you can make while keeping that board is to get an actual true 400 MHz FSB Northwood.

The fastest I have found at a reasonable price in my country is the 2.0 512KB 400MHz P4 . Should I buy it?

crapasanya wrote on 2026-05-29, 14:12:

MagefromAntares wrote on 2026-05-28, 23:28:

onethirdxcubed wrote on 2026-05-28, 23:04:

If you have 1.8ghz/400/256 that's a Willamette core not a Northwood.

Thanks for correcting me on that, I haven't noticed that 256 is an invalid L2 Cache size for a Northwood.

For the OP: True Northwoods have a 512KB L2 Cache while Northwood core Celerons have 128KB L2 Cache, so as onethirdxcubed suggests the best upgrade that you can make while keeping that board is to get an actual true 400 MHz FSB Northwood.

The fastest I have found at a reasonable price in my country is the 2.0 512KB 400MHz P4 . Should I buy it?

I cannot make the decision for you to buy it or not, that should be based on your own choice, however I can give you what are the expected changes:
1. The doubled cache size will have the most effect on data heavy applications, however the SDRAM will most likely still hold the system back, the Northwoods were usually paired with DDR ram for this reason, so it will increase the performance in these scenarios, but due to the SDRAM you still cannot expect it to be a good performer just better than the Willamette.
2. The clock speed increase of 0.2 GHz is quite small, applications that work with very little data doesn't benefit from the cache increase and will only experience a very minor, most likely barely felt, performance increase.
3. Northwoods were made on a smaller die scale 130 nm vs Willamette's 180 nm, which means that it will run colder. While this makes Northwoods surprisingly good overclockers if the MB supports it, be aware of SNDS(Sudden Northwood Death Syndrome), which may happen when increasing voltage when overclocking.

I would link a page containing benchmark with the same frequency Willamette and Northwood, however the single benchmark I known of that compares them on a SDRAM platform are gone from the net, cannot even find it on archive.org, and linking benchmarks were the memory type is different SDRAM vs DDR would not show a honest picture of the performance increase to be expected.

Due SDR being slower than DDR, having 2x L2 is actually the most important aspect of Northwood.

This computer is from Intel dark times. Ridiculously expensive RDRAM, ridiculously slow SDRAM, ridiculously slow Celerons, $1billion a year bribes to DELL for not switching to AMD https://fortune.com/2007/02/15/suit-intel-pai … -use-amd-chips/ Its Ls everywhere you look.

@crapasanya
I have paired my 845 system at first time with a 2.66Ghz Northwood. Then i've replaced it with the 2.8Ghz Northwood, to easily reach 3.0Ghz with OC.
In combination with "the easy adjustable" DIP switch, i can choose between the settings:
2800Mhz (21 x 133.33Mhz) ;
2100Mhz (21 x 100.00Mhz) ;
1400Mhz (21 x 66.67Mhz)
My mainboard has the same chipset than your IBM 49P4384, but :
it has DDR ram instead of SDram... (i think, i had installed DDR 333 ram...)
it has that DIP switch for choosing between 66 to 133 Mhz.
it's obviously doing these high FSB in OC, but it's possible. But may not every i845 board can do the same...

The fastest setting, i've tried was: 3000Mhz (21 x 143Mhz). But for this setting, i need a FSB tool in windows 98...

crapasanya wrote on 2026-05-29, 14:12:

The fastest I have found at a reasonable price in my country is the 2.0 512KB 400MHz P4 . Should I buy it?

If it really does seem like a reasonable price, then I'd say go for it.
(Though I am curious what this "reasonable price" is, as I'd like to see/compare it to what I can find here locally. 😀 )

About 15 years ago, I used to find a lot of P4 systems thrown away on the street (I was living in the US then.) One such came with a 1.7 GHz Willamate - basically nearly the same thing as your CPU (same FSB and L2 cache). I put XP SP2 and used this system for a while as a replacement for my 1.4 GHz Duron Applebred PC. Compared to the 1.4 GHz Duron Applebred (with its measly 92 Kb of L2 cache), the 1.7 GHz P4 did feel noticeably faster, particularly in Half-Life 2 -based games I was playing at the time - mostly HL2 DM (and I see some Half-Life 2 action on your screeshots too, so I can relate here 😁 ). In particular, I was mostly getting around 20 FPS on average at 640x480 windowed mode on my Duron PC (though that was also partly due to the crappy Radeon 9200 SE I was using too.) When I jumped to the 1.7 GHz Willy, I basically managed more or less the same FPS (again, mainly a limitation of the Radeon 9200 SE), but the dips in FPS in HL2 DM (particularly when there was a lot of object physics involved) weren't anywhere as terrible as they were with the 1.4 Duron. With the Duron, I'd regularly see dips as low as 11 FPS when many wooden crates/boxes broke. With the Willy, I never dipped below 15. I realize these are laughable numbers nowadays (and even back then they were), but being a low-spec gamer most of my life 🤣, I can tell you that every frame counts once you dip below 20.

Then I found an nVidia GeForce FX5600 card for cheap ($5). I put that in and -WOAH- I could now up the resolution to 800x600 while maintaining the same or better FPS... often hoovering around 25's (whereas with the Radeon 9200 SE, this was mostly in the low 20's and at lower 640x480 resolution.)

Then I found another P4 system - this one with a completely dead motherboard, but with a working 2.0 GHz P4 Northwood. So I swapped the 1.7 GHz Willy for the 2 GHz NWood. The system felt faster yet again, but not as large a jump when I switched from the 1.4 GHz Duron to the 1.7 GHz P4 Willy. Mainly it was the low FPS dips that improved again, very rarely dropping below 18 at the same spots that I saw 15. Again, these are small improvements, but not insignificant. Come to think of it, these FPS numbers do match the CPU upgrade... with the 2 GHz Northwood indeed being 20% faster than the 1.7 Willy just based on the core speeds (in practice, probably even more due to twice the cache.)

So the upgrade from the 1.7 Willy to the 2.0 NWood was worthwhile IMO. Actually, the other unsaid upgrade is that the 1.7 GHz Willy was quite hot and power hungry - about 80W TDP under full load / gaming. The 2.0 GHz NWood not only was slightly faster but also ran much much cooler due to using around 65W or less when gaming. So it was a win-win in my book.. and even more so to my motherboard, since it's one of those rarities that does not have a P4 12V CPU connector. Therefore, my PSU was also happier. Basically, once I swapped the 1.7 Willy for the 2.0 NW, everything in the entire system ran significantly cooler.

Given that your motherboard has bad caps already (and you really should change them sooner rather than "later" 😀 ), upgrading your 1.8 GHz Willy to a 2 GHz NWood, you'd probably reduce the stress on the board significantly. So if you intend to keep the board long term, I think the 2 GHz P4 would come as a small but not insignificant upgrade, both in terms of performance and heat reduction.

In regards to recapping your board... I see it has a mix of good caps brands and known bad cap brands. The purple/dark blue caps with "X" -shaped vents that are bulging around the CPU area appear to be either OST RLX or perhaps GSC/Evercon LE/ME. Those are really the only ones you need to change, though. The caps with the "T" -shaped vent on top are Matsushita/Panasonic and can be left alone (and those are probably all that's holding your board together from stopping itself to work.) I also see the rest of the board appears to use Rubycon caps, so those can stay too.

Your PSU is another hardware item I feel uneasy about as I can't recognize who's its manufacturer. It looks very cheap, though. The lack of real safety certificates on its label screams "full of crappy caps and ready to blow up at any moment's notice". Might want to look into it or replace it eventually (but again, probably sooner rather than "later" 😉 ).

The case looks nice, though - actually very era-appropriate too with the missing bay covers, hehe.

The monitor - I have its bigger brother/cousin here: a 19" SyncMaster 910 or 920 or something like that... in silver. It's missing 3 of the control buttons on the front, though, so not in a as-pretty state as yours. But hey, it was a dumpster find, so I can't complain. Just needed a few caps changed to get going.

Now the JBL speakers... those I think we all approve of (I actually envy 😀 ) - very nice!

P.S. To further play detectives with the pictures here... I see you got schuko wall plugs and wallpaper, so can I safely assume you're somewhere in central or eastern Europe? 😁

Tons of P4 on ebay from China ~$10 free shipping. For example
"Intel Pentium 4 P4 2.6GHz SL6PP 512 KB 400MHz Socket 478/N CPU Processor For PC" 50 sold 50 available $10
"Intel Pentium 4 P4 2.8 GHz 512K 400MHz SL7EY Processor Socket 478 CPU" $11
"INTEL PENTIUM 4 PROCESSOR 2.8GHZ/512K/400MHZ（SL7EY）Socket 478/N CPU" 5 sold 5 available $15

rasz_pl wrote on 2026-05-30, 23:22:

Tons of P4 on ebay from China ~$10 free shipping. For example "Intel Pentium 4 P4 2.6GHz SL6PP 512 KB 400MHz Socket 478/N CPU Pr […]
Show full quote

Tons of P4 on ebay from China ~$10 free shipping. For example
"Intel Pentium 4 P4 2.6GHz SL6PP 512 KB 400MHz Socket 478/N CPU Processor For PC" 50 sold 50 available $10
"Intel Pentium 4 P4 2.8 GHz 512K 400MHz SL7EY Processor Socket 478 CPU" $11
"INTEL PENTIUM 4 PROCESSOR 2.8GHZ/512K/400MHZ（SL7EY）Socket 478/N CPU" 5 sold 5 available $15

China is where all the scrapped P4’s went