Yes, this is the best way to go...along with a nice triple-channel RAM upgrade.
I agree with you 100%. Tarry and those
new $325 X5690s*/ from Adventis Systems [
http://www.ebay.com/itm/New-INTEL-XE...-/371206102426?afsrc=1&rmvSB=true ] will be gone. Admittedly, when you update firmware from 4,1 to 5,1, the SMC version stays at 4,1. But, so what? I began hacking mine soon after the 5,1's updated firmware was released. Since I'd run my MP4,1 with SMC Fan Control and did so afterwards, I didn't and don't consider the mismatch to be an issue. If you do the firmware hack, after you've completed it:
(1) reset SMC (unplug all power sources to the MP (and this includes any auxiliary power supplies for GPUs, etc.) - Next, I wait at least 60 secs and push the power button in, holding it in for at least another 30 secs) and
(2) reset parameter ram (Before startup chime sounds hold down all four keys [ Option/Command/P/R ] simultaneously - I hold all four of them down for at least two chimes).
*/ Mine are the tray version of the SLBVX, but were factory sealed in plastic with protective covering.
I recently purchased a large number of them from Aventis because:
(1) these CPUS are the top of the line for Westmere processors (if you buy slower CPUs you might find soon yourself trying to touch your behind with the heel of one of your feet shortly after the new X5690s are all sold out),*
(2) they were/are selling for a deep discount (once they sold for $1,600 ea.) and now are selling at the lowest price that I'd (I've) seen,
(3) they are new and warranted (so they hadn't been improperly overclocked like many used CPUs for sale probably have been, unless they were pulled from servers [and that's where they were first and only installed - not overclockable there)], or only used in Macs - not overclockable there also), and
(4) the company is located not very far from me.
N.B. -
(1) On June 09, 2013, Intel announced discontinuation of, among others, X5690 Xeon CPUs. The last order date for those CPUs was December 27, 2013 [
http://www.cpu-world.com/CPUs/Xeon/I...614X5690).html ]. So Intel’s warranty may not apply since they probably aren’t being manufactured by Intel any more. However, Aventis Systems provides a one year limited warranty.
(2) The firmware/SMC mismatch can be a reason for not doing the upgrade, if one simply loves a factory match. For me however, it wasn't a good reason not to upgrade.