Can someone explain AMD processors for me....

[optinox]

Hi,

I"m just wondering something about the AMD processors, I was checking out this website (I'll post it at the bottom of my post) and they have a listing of the different kinds of AMD XP series cpu's, I always thought that the higher the series the faster the cpu was, such as XP 2100+, XP2400+, XP2600+, ect...but I was looking at the cores which had different one's such as Thourobred, Palomino, Barton, and Thorton which is better I have no idea, but what confused me a bit is how on some of the cpu's that were higher in series had higher FSB but a lower operating frequency, check out the link...hopefully someone of you pro's out there could explain this to me, thanks.

http://www.newegg.com/app/ViewProduc...codevalue=4159

[SoSl0w]

Barton is the latest core besides 64-bit and has the largest cache. It should preform better than one with a 256cache at the same speed or even one that is a little higher. Speed isn't everything but it does make difference in certain areas where a large cache would make little difference.

[John Prophet]

yeah..if the series number goes higher...like from 2800 to 300 or whatever....and yet the spped stays the same or decreases.....that means that the cache increased to make up for the speed difference.

That PR rating..the number they give for it, like 3200+ etc...it can increase by upping the speed, OR..upping the cache...so the ones with higher numbers yet lower speeds surely have more cache. (cache is very fast memory built onto the cpu, it stores commands and stuff so that if the cpu needs to run em again, it doesnt have to go to the slow system ram or hard drive etc...so the bigger the cache, the more stuff it stores, the faster it is...thats a very simplified explanation)

JP

[jmichna]

The PR (performance rating) started as an AMD Marketing tool.
It started as a way of comparing the performance of the Model 6 (Palomino) processors compared to AMD's Thunderbird (Model 4) CPUs. Refinements in the design of the Model 6 CPUs provided the same performance level as the Model 4 CPus, but at lower clock speeds (lower frequencies). AMD carried on the PR as they migrated to the Model 8 (Thundertbird), Model 10 (Barton) and now the new family of 64-bit CPUs.

A better processor design is capable of doing more work per clock cycle, so a Barton Model 10 running at 2167mHz (PR3000+) is rated to do as much (or more... the "+") work as a Thunderbird Model 4 running at an actual 3000mHz. (Note: I seriously doubt anybody ever got a T-Bird up to 3000mHz unless they used LN.)

Peformance differences are affected by a lot of things besides cache size. I'm sure some one here at TechIMO knows a lot more about CPU architecture and design, and can either explain what things got better/more effective at a given speed, or point to a resource.

A lot of people think that the PR is supposed to show equivalence between an AMD and an Intel CPU. AMD Marketing never officially proposed or promoted this, but didn't actively deny it when people made those assumptions. Besides, in running a whole variety of different benchmarking programs, you will usually find that the PR rating of an AMD CPU usually does match quite well with an equivalent clock-speed Intel CPU.

[John Prophet]

---> "The PR (performance rating) started as an AMD Marketing tool.
It started as a way of comparing the performance of the Model 6 (Palomino) processors compared to AMD's Thunderbird (Model 4) CPUs."

-----

actually I think it started way back with the K6..as AMD wanted to show how it performed compared to the P1

They just dropped it...and didnt need it during the Athlons first glory days....but then Intel went crazy with clock speeds...so I suppose AMD felt compelled to go back to it.

it does make sense though....otherwise the average man on the street sees the big number (intels mhz) and thats all he has to go by...when in fact there is a lot more to the cpu performance.

[jmichna]

Originally posted by John Prophet
---> "The PR (performance rating) started as an AMD Marketing tool.
It started as a way of comparing the performance of the Model 6 (Palomino) processors compared to AMD's Thunderbird (Model 4) CPUs."

-----

actually I think it started way back with the K6..as AMD wanted to show how it performed compared to the P1

They just dropped it...and didnt need it during the Athlons first glory days....but then Intel went crazy with clock speeds...so I suppose AMD felt compelled to go back to it.

it does make sense though....otherwise the average man on the street sees the big number (intels mhz) and thats all he has to go by...when in fact there is a lot more to the cpu performance.

John,
You're right... the term "Performance Rating" (PR) did start with the K5 vs P-I. One of the earliest I can remember was the K5-PR75 ("equivalent" to a Pentium 75mHz) . The "XP" (performance) rating is properly associated with the Palominos and newer chips vs the TBirds... I got a bit carried away -- and sloppy -- with history.