Performance:
I ran some Sandra benchmarks at default rating of 1900+, then compared them with the 1900+ Palomino scores. All images on this page will enlarge when clicked.

  
Thoroughbred - Sandra CPU - Palomino

  
Thoroughbred - Sandra Multimedia - Palomino

  
Thoroughbred - Sandra Memory - Palomino

No performance difference between the two cores. As expected, 3DMark2001SE shows them also virtually identical:

  
Thoroughbred - 3DMark2001SE - Palomino

I continued testing by raising the FSB, running more tests at 150, 166, 185 and 195 - the scores and any difference remained constant.

Overclocking:
It would be a fair guess that you're reading this because you want to know how it overclocked. Well, I can't disclose that due to.. only kidding! The first thing that struck me was the drop in core temperatures on the Vapochill at default voltage. Usually the Vapo will show a LCD temp display of around -16C at idle, with the the lower voltage of the Tbred the idle temperature reading dropped to -20C. Recording accurate temperatures when dealing with CPU's is beyond any equipment I have here, so let me just say that there is, as expected, a definite drop in CPU temperature with this new core. This I assume is directly related to the lower voltage of the Tbred. Now that is always good news, whether you’re using a FOP38 or a Vapochill!

Initially, adding more voltage was easy. When I reached 2.0V I had a moment of clarity, realizing that this is 0.4V above default and getting risky in my opinion. I can hear you thinking "I would have done 2.2V straight away", well, buy one as soon as you can and let me know how it goes. :) I raised the Voltage to a maximum of 2.1 Volts Core and 2.85 Memory and the WCPUID shots below tell the story.

This is the Tbred running rock solid and stable, using Prime95 and looping 3Dmark. The new core has a very stable 'feel' to it, and I doubt more intensive usage would cause the BSOD gods to rain on this parade.

The shot below is far from stable, I am able to move files across network and use a browser, but any sort of Benchmark or CPU intensive test would cause a reboot.

Lastly a quick FSB shot,nothing seems to have changed here, the Tbred handles the big FSB just as well as it's older sibling.

Conclusions:
The new Thoroughbred create less heat, by way of reduced core voltage, than its Palomino counterpart. For that reason alone it should interest overclockers. I have tested quite a few Athlons and I have had higher Overclocks from some, however, the three Thoroughbreds I tested all performed on par with each other. The difference between best and worst stable overclock was 20MHz. I think this speaks volumes for the yields, and I think as the 0.13 process matures and new steppings appear, we will see much greater things from these cores in the overclocking department. Stay tuned..