Intel Pentium 4 641 1-core LGA775

The Pentium 4 641 is a 2006-era single-core chip with a 385 PassMark score that costs $90 on the used market. It's only worth buying for period-correct retro builds or as a drop-in replacement for a dead LGA775 CPU. For anything else, even a decade-old i5 will run circles around it for less money. Authentic, but brutally slow by modern standards.

Let's talk numbers. The PassMark multi-thread score is 385, which lands this chip in the 12th percentile of all CPUs in our database. That's not just slow, it's one of the slowest things we've tracked. The single-thread score of 572 is slightly better at the 11th percentile, but that's like being the fastest kid in remedial gym class. Hyper-Threading gives you two logical threads, but they're sharing one physical core, so don't expect any real multitasking magic.

The 3.2GHz clock speed sounds impressive until you remember this is NetBurst architecture, which was famous for high clocks and mediocre actual performance. The 800MHz front-side bus and 2MB L2 cache help a bit, but modern CPUs do more work per clock cycle by a ridiculous margin. For retro gaming or running period-correct software, it'll feel authentic. For anything else, even web browsing will make you question your life choices.

Stacking this against modern competitors is almost unfair, but let's do it anyway. The AMD Ryzen 9 7900X scores somewhere around 50,000 in PassMark multi-thread, which makes the Pentium 4's 385 look like a rounding error. Even the Dell Xeon E5-2637 V2, which is itself ancient by modern standards, will crush this chip in every benchmark. The be quiet! Ryzen 3 Dark Rock Pro 5 is a cooler, not a CPU, so that's a weird listing on Amazon's part, but the Ryzen 3 it's designed for would also demolish the Pentium 4.

The real comparison here is against other retro chips. If you're building a Windows XP machine, you might also look at Pentium D dual-cores from the same era, which give you actual two-core performance for similar money. Or a Core 2 Duo, which was the chip that made NetBurst obsolete. The Pentium 4 641 is fine for authenticity, but it's not even the best retro option out there.

Here's where things get weird. This chip costs $90 on Amazon right now. For that money, you could grab a used Ryzen 3 or an old i5 that would run circles around this thing while sipping power. The affordability score of 32.3 out of 100 tells the story, it's not a good deal by any modern metric. But value is relative when you're building a retro rig.

If you need this exact chip to complete a period-correct build or replace a dead CPU in an old machine you're keeping alive for nostalgia, then $90 might be worth it to you. Just know you're paying for authenticity, not performance. The efficiency score of 12.9 out of 100 means you're also paying more in electricity over time than you would with literally any modern chip.

The Intel Pentium 4 641 is a fossil from 2006 that somehow still shows up on Amazon. This is a single-core Cedar Mill chip running at 3.2GHz with Hyper-Threading, so it pretends to have two threads. Back in the day, this was a decent budget desktop CPU. Today, it's a museum piece that costs $90 on the used market, which is honestly kind of funny when you think about what $90 gets you now.

Who is this actually for? Retro PC builders trying to recreate a Windows XP era machine, or someone nursing an ancient LGA775 board that needs a drop-in replacement. That's about it. The 2MB of L2 cache was generous for its time, and the 65W TDP won't melt your motherboard. But make no mistake, this is not a daily driver in 2025.

The interesting thing here is the pricing. At $90, you're paying collector prices for a chip that scores 385 in PassMark multi-thread. For context, a used Ryzen 3 or even an old i5 from a decade ago will absolutely obliterate this thing for similar or less money. But retro builds have their own logic, and the Pentium 4 641 does have that authentic NetBurst charm, if you can call it that.

Skip this if you're building any kind of daily-use computer. The single-core design and 385 PassMark score mean even basic tasks will feel sluggish. You're also locked into a dead socket with no upgrade path, so you can't start here and improve later. If you need a cheap functional PC, look at used office machines with 4th gen or newer Intel chips, they're often cheaper than this CPU alone and vastly more capable.

Also skip it if you're just trying to revive an old LGA775 system on a budget. A Core 2 Duo E8400 or E8500 will give you real dual-core performance for a fraction of the price, and they drop into many of the same boards. The Pentium 4 641 is only worth it if you specifically want the authentic NetBurst experience for a period-correct build.

If you're building a period-correct Windows XP machine and you specifically want a Cedar Mill Pentium 4, this chip will do the job. It's authentic, it runs cool enough, and the 2MB cache helps with older games. Just don't expect to do anything modern with it. Web browsing, video playback, even basic office work will feel like wading through molasses.

For everyone else, this is a hard pass. The $90 asking price is collector money, and there are far better retro options if you're just trying to get an old system running again. A Core 2 Duo or even a Pentium D will give you more performance for less cash. Buy this only if you know exactly why you want it.