Smugblog wrote a review about the Sun Fire T1000 server and compares it to "Olde Faithful", a rackable C1000 with two dual-core AMD Opteron 270HE 2GHz processors.
I'm not a big believer in the raw clock speed of CPUs, especially after watching our 2GHz Opterons clobber our 3GHz non-Woodcrest Xeons, but in this case I'm gonna give Sun the benefit of the doubt and guess that their clock speed is probably "high quality," just like AMD's.
CoolThreads' 8 cores x 1.0GHz = 8GHz. Olde Faithful's 4 cores x 2.0GHz = 8GHz. My hypothesis is that both are going to deliver roughly equivalent performance when it comes to the $/CPU portion of the equation. I predict a tie under load (which is what we care about most), but that when not loaded, Olde Faithful will serve photos faster.