What advantage does my Prescott core CPU have over a Northwood core?
February 13, 2005 8:38 PM   Subscribe

IntelFilter: What (if any) advantage does my Prescott core CPU have over a Northwood core one? [MI]

I'm currently using a Pentium 4 3.20E (Prescott) and have been wondering for quite awhile if it actually has any advantage over one of the older Northwood cores. I know the Prescott has a larger cache, I know that due to a longer execution pipeline it is supposedly somewhat slower, and I know that it runs freaking hot.

The problem is I have no idea if overall it's actually more useful than a Northwood. I don't know what exactly the larger core will do for me, I don't know if there's anything about that longer execution pipeline that actually good for something, and I can't seem to sort through all the marketing bullshit to find out if MY chip is actually useful, or if Prescott is only something that will benefit future chips.

Slower benchmarks on games (no idea if the real world performance is lower), vast heat output, and a problem with some motherboards that cause windows to not boot if you install Service Pack 2. That's about all I understand clearly. Can anyone here explain to me what this chip is actually good for? Is a Northwood better? I've tried googling this for a long time (starting before I bought it a few months back) but I'm finally admitting defeat.

(please excuse me if any of that is redundant or unclear, I'm sick right now and having quite the problem being coherent)
posted by Stunt to Computers & Internet (5 answers total)
 
There's a great article on the failures of the Prescott architecture up on AnandTech.

It's complicated. As far as I can tell, Prescott has Hyperthreading, which will help for "streaming" type apps that don't fill up the cache, like video or music decompression. It also has particularly good ALU performance, since its ALUs are running at twice the speed of the processor.

But it's pretty inefficient with its cycles, compared Hz-for-Hz to other architectures. It does an amazing amount of control trickery -- all sorts of weird forwarding and branch prediction. The rule of thumb is that 1 Banias Hz is worth 1.5 of a Prescott Hz. (I don't know Northwood's rule of thumb). Prescott has also hit a GHz ceiling.

That said, AnandTech slightly prefered the Pentium 4 570 (I believe that's Prescott) to the Pentium 4 Extreme Edition (I believe that's Northwood).

Though I seem to remember they liked the Athlon 64's out of AMD even more. Definitely check out their Half-Life 2 and Doom III timings. Demo timings are as close as we're going to get to understanding these performance issues, in the end.
posted by maschnitz at 11:12 PM on February 13, 2005


I believe the longer pipeline was meant to allow the Prescott to run at much higher clock speeds, which would compensate for it's inefficiency. Not only did that not happen, but it's also an encumbrance to you since a 3.2 GHz Prescott is less efficient than a 3.2 GHz Northwood. The Prescott does have some improved architecture for certain things, but they're not very interesting.

maschnitz: I believe the P4 has always had double speed ALUs, and HT is available in later Northwoods.
posted by cillit bang at 12:40 AM on February 14, 2005


The Pentium 4 570 is the 3.8GHz P4 that's using the new LGA 775 dealie (with the PCI-Express boards). The Extreme Edition chip wasn't a Northwood, as far as I know that overpriced thing uses the Gallatin core (I think it's from the Xeon MP chip).

From what I can see my damn chip was made in a way that enabled future chips (like the new LGA 775 ones being made and I think the dual core Smithfield line coming up) to get faster. I don't understand why the hell they built a chip that didn't NEED it though. If a Northwood can hit 3.2, then why the hell is there a prescott one? Bah. I looked through Intel's site to see if they had any sort of explanation for why someone would buy this thing, but couldn't come up with anything.

Hmmm...so, is there any reason for me to stick with this thing rather than replacing it with a 3.2 Northwood? Is the 1MB cache actually going to make some things run better, or is it just helping to compensate for the numerous downsides? Upgrading to one of the even newer ones (the 5xx line) isn't an option because I'm not going to ditch all the hardware I recently bought for this thing just to use overpriced stuff for a PCI-Express board. Or did I just get conned into buying a very sub par chip?

Thanks for the attempted help so far; the epic quest continues.
posted by Stunt at 9:24 AM on February 14, 2005


OH, I get your question now.

The reason is, Prescott failed. They expected it to get to 5Ghz. It didn't.

See that article I linked to, above.
posted by maschnitz at 6:18 PM on February 14, 2005


Yeah, after all this time I have to agree. If I could find a Northwood version of the chip I use I'd just swap it out. Even with good water cooling I can't make my workstation as quite as I'd like; this thing is HOT. Oh well, thanks a lot Intel.
posted by Stunt at 8:46 PM on December 30, 2005


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