Intel randomly enabling and disabling features across their processor lines drives me crazy. I want to upgrade my fanless Panasonic R3 subnetbook —based on a Pentium M 1.2 GHz with a max TDP of only 5.5W(!)— to one with a processor supporting a 64-bit instruction set, Intel VT-x for some light virtualization work with KVM, and as low power as possible. I started by researching the Intel Atom processor family, hoping that Intel would have made VT-x a standard by now.
My hopes quickly got crushed.
Read this list of processors supporting VT-x: it doesn't even make sense. The lowest power Atom processors Silverthorne and Lincroft (Z5xx, Z6xx) support VT-x but are 32-bit, while the slightly more power hungry ones Diamondville and Pineview (N2xx, 2xx, 3xx, N4xx, D4xx, N5xx, D5xx) are 64-bit, but do not support VT-x.
There is really no choice for me but to aim at the Celeron or Core processor families. After some more research I established a list of the lowest power 64-bit processors, VT-x-enabled, and based on the Nehalem microarchitecture. Because these processors have the CPU and the GPU on the same chip, the TDP includes both. I restricted myself to those with a max TDP of 18W. The next step in terms of power consumption is 25W, then 35W, which is too high to my taste. I also excluded Core i7 processors which are just more expensive i5 models with more cache or higher Turbo Boost frequencies, which is not worth the premium in my opinion.
- Celeron U3400: 2-core 2-thread 1.06GHz
- Celeron U3405: 2-core 2-thread 1.06GHz (support ECC memory!)
- Core i3-330UM: 2-core 4-thread 1.2GHz
- Core i3-430UM: 2-core 4-thread 1.2GHz (supports Turbo Boost)
- Core i5-520UM: 2-core 4-thread 1.06GHz (supports Turbo Boost, VT-d, and AES-NI)
- Core i5-540UM: 2-core 4-thread 1.2GHz (supports Turbo Boost, VT-d, and AES-NI)
Now remains to find decent subnetbook models using the above processors...