All tests between the 2 processors with the same clock speed but with different FSB are finished!
While it was obvious that a FSB 333 processor is better than a 266 one the question is: how much better? Is it worthwhile to spend some money to upgrade from a Athlon XP 2000 to a Sempron 2400?
The answer is YES! The Sempron is 6.72% faster than the Athlon XP. While both are based on the Thoroughbred core having a 333 MHz FSB makes a difference that can be felt, especially in games!
Also taking into account that Sempron is considered a low end part and Athlon XP is considered a high end part on socket 462 the prices for Semprons are actually lower!
Of course there are Athlon XP with a 333 MHz FSB that are better than any Sempron but if you got a 266 MHz processor than it is worth to change it to a Sempron.

Now one question remains: how about the faster clocked processors?
There are 2 more socket 462 CPU's with the same clock speed but different FSB: Athlon XP 2400 Thoroughbred - B and Sempron 2800. Both have 2000 MHz but the Athlon has a 266 MHz FSB while the Sempron has a 333 MHz FSB.
I got the Sempron last week and I did test it against the Athlon.
I am not going to put up the screenshots but the advantage of the processor with the faster FSB remains: Sempron is 6.62% better than XP 2400. So despite the higher clock speed there is always an advantage by going with a CPU that has a 333 MHz FSB.

Now that we have seen the advantages that comes with a 266 MHz FSB versus a 200 MHz one - when I tested 1200C versus 1200B - and a 333 MHz FSB versus a 266 one - Sempron 2400 versus XP 2000 - it would be logical to test the last and highest performance socket 462 processors with a 400 MHz FSB.
However there are only 2 widespread CPU's on SOCKET 462 with a 400 MHz FSB: Athlon XP 3000 part number AXDA3000DKV4E and Athlon XP 3200 part number AXDA3200DKV4E - Sempron 3300 is a rebadged XP3200. There are some rare Athlon XP manufactured in very small quantities for OEM's with a 400 MHz FSB, however they are very difficult to find.
Furthermore there are no CPU's with a 333 MHz FSB with the same clock speed and the same amount of cache as those 2 even if we take into account those OEM only CPU's.
It is impossible to test the final iteration of the K7 architecture with a 400 MHz FSB because there are no 2 chips with the same clock and the same amount of cache!

Despite the fact that we can not test the advantages of the 400 MHz FSB against 333 MHz we shall continue testing the last remaining K7 generations: Palomino and Barton versus their previous iterations.
Palomino versus Thoroughbred has been tested at 2000 (P-Rating) MHz with both models and they perform practically the same - WITHIN 3% - so there is no performance advantage by going with a T-bred, however you get a significantly lower TDP and operating temperature not to mention higher frequencies with 2100 - 2700 models. However improvements brought by Palomino versus the older Thunderbird has not been tested.
The last series of tests is reserved for Barton versus Thoroughbred - practically 512 KB of cache versus 256 KB.

Palomino is the second generation K7 for socket A and introduces a few notable changes compared to its predecessor:
- SSE which is extremely useful even with the 2000-2004 time period when not every single game and program requires SSE!
- performance rating for the K7 in order to keep up with the ever increasing frequency of the P4
- 10% faster than Thunderbird clock for clock according to period correct reviews: https://web.archive.org/web/20041013113816/ht … on-xp-1800.html ; https://www.anandtech.com/show/835
The last affirmation is exactly what are we are going to test! Clock for clock Palomino versus T-bird with newer drivers, hardware and tests to see if the above 10% is true today!

There are 4 models with the same FSB and frequency:
- Athlon 1333 part number A1333AMS3C, 70W TDP and Athlon XP 1500 part number AX1500DMT3C, 60W TDP
and
- Athlon 1400 part number A1400AMS3C, 72W TDP, named from now on 1400C and Athlon XP 1600 part number AX1600DMT3C, 62.8W TDP named from now on XP.
I have all 4 models however for testing I choose the 1400C and XP 1600.

The platform is the same as the last time:
- Abit AN7 with nforce2 ultra chipset
- 2*1gb DDR at 2-2-2-5 timings from Kingmax
- geforce 7600GT from Leadtek - to keep the results comparable with the Palomino/T-bred 2000 and Thunderbird 1200B/1200C
- Eizo 21.6 monitor with 1600*1200 resolution
- software: Windows XP SP3 with no updates; chipset drivers 5.10, geforce drivers 93.71, msi afterburner 4.30, fraps 1.9D.

Pictures with the legendary AN7 can be seen in this topic dozens of times, I will not put them again.In order for 1400C to work in Abit AN7 a BIOS reset is required and manually setting of the CPU in the Softmenu: 10.5 multiplier with a 133 MHz FSB.
Now for the obligatory CPU-Z screenshots:

And the Everest 5.50 system info with every single piece of hardware correctly detected:

In the case of Palomino 1600 I simply dropped in the new CPU which was recognized on the spot with the correct multiplier and voltage and the system was ready to go!
Of course, I forgot to take screenshots with Everest and CPU-Z!! I will take some screenshots one of these days and put them on the forum but for now let's concentrate on the results!

1. The first benchmark is Code creatures pro at 1024*768 default settings - that means no AA as it is the only setting available - and no sound:
1400C
PALOMINO 1600

And the first victory belongs to ... Thunderbird 1400C?!?

2. Code creatures pro at the same 1024*768 settings with sound:
1400C
XP 1600

And for the second time Thunderbird wins ??!! By 7.5%?!
That can't be right! All period correct reviews have Palomino in front!

3. We add AA 4X - and test again at 1024*768 with no sound:
1400C
XP 1600

For the third time in a row Thunderbird 1400C wins against Palomino 1600! This is really fishy!

4. Same 1024*768 resolution with AA 4X and sound:
1400C
Palomino 1600

Incredible at it may seem Thunderbird wins again!

5. We increase the resolution to 1280*1024 max settings, no sound the first time:
1400C
Palomino 1600

Thunderbird feels at home in Code creatures pro as it wins again against the equally clocked Palomino 1600!