Which 1GHz is faster, Underclocked Athlon XP or Tbird?

[dullard]

Suppose I had a 1GHz T-bird (266 MHz fsb).
Suppose I had a 1GHz T-bird (200 MHz fsb).
Suppose I had an Athlon XP underclocked to 1GHz (with only the CPU speed changed, no other component changed).

Everything else is the same (as best it can be).

Which do you think is faster?

 

[CubicZirconia]

The XP should be, although I'll bet you're going to show some crazy benchmark that says its not...

 

[joohang]

About the same. Palomino should be slightly faster.

 

[dullard]

Thanks for your votes. It is what I expected for a result.

I asked this since I was in a debate about AMD's PR ratings. As we know, they are based on Tbird speeds. There are two reasonable possibilities when using that base:
A) PR rating = 1.5 * XPspeed - 500 (A linear formula)
B) PR rating = .148 * XPspeed^1.282 (A power formula)

Check of those rating formulas:
XP speed / Actual PR rating / PR rating (A) / PR rating(B)
1333       / 1500+             / 1500+          / 1501+
1400       / 1600+             / 1600+          / 1598+
1466       / 1700+             / 1700+          / 1696+
1533       / 1800+             / 1800+          / 1795+
1600       / 1900+             / 1900+          / 1896+
1666       / 2000+             / 2000+          / 1998+
1733       / 2100+             / 2100+          / 2101+

Obviously if you round the formula (B), then you have the same numbers within this range. However with extrapolations, things get completely different.

If you extrapolate backwards to 1 GHz formula (A) says that a 1GHz XP is the same exact speed as a 1 GHz Tbird. Obviously most people disagree with this (The XP has some architectural improvements over the Tbird). So I argue that formula (A) is wrong. Formula (B) predicts a PR rating of 1038+ for an underclocked 1 GHz Athlon XP - slightly faster than the Tbird. So I argue that formula (B) is better.

Extrapolating forward is the interesting part though. At higher speeds formula (B) gives a much higher PR rating for the same Athlon XP chip. Basically formula (B) will overexaggerate the performance.

Your thoughts? (Please keep it focused to the PR rating based on Tbird - no off topics)