T5440 == an E25K?? HA!
A T5440 is no where near equal to a E25K, that is close to the silliest thing I've ever heard. A T5440 has 16 cores on two chips, all those cores share onboard cache. A thread gives absolutely no CPU number crunching power in fact it lowers it due to scheduling. Where threads give benefits is when the CPU is waiting on some other task: i.e. storage, etc. you can schedule something else. It's pure stupidity to say it's anywhere near a E25k, it's barely a v1290.
Talking Oracle, let's compare a T5440 vs a HP Dl580:
DL580= 4x 4 core 2.93 Ghz CPU's = total 46.88Ghz
T5440 = 2x 8 core 1.4 Ghz CPU's = total 22.4Ghz
DL580 = 2x 4M L2 cache per socket = 32M total L2 cache
T5440 = 4M L2 cache per socket = 8M total L2 cache
Assume list price for Oracle Enterprise RAC ~= $60k/CPU
DL580 = 16 cores * 60k * .5 = $480k
T5440 = 16 cores * 60k * .75 = $720k
So for less than half the total Mhz processing power, a quarter of the L2 cache, and $240,000 more I can use a T5440 for Oracle RAC. This my friends is why the Oracle is running from the Sparc architecture, and why saying the T5440 is anything near a E25k is friggin silly.