Of course upgrades like this always raise the question if it's worth it (i.e. putting a lot of money into upgrades for an older model vs selling it and getting a later model (either used or refurb) with faster CPUs, ram, system bus, PCIe 2.0, etc.) so earlier this morning when I recd that email I checked eBay for X5365 CPU sales and saw one auction that had them for $395 each (free shipping - claimed to be 'server spares/tested good') - but after getting pulled away to fix a water leak - this afternoon I refreshed the eBay search and that auction was no longer listed. (With the lowest price now listed at $599.) At $1200 (for a dual CPU swap, not counting the potential risk) I'd consider what the Mac Pro as-is would bring if sold and then add that $1200 to that figure and see what that total $$$$ would buy as far as a used 2008 or a used/refurb 2009 Mac Pro.
BTW - the reader that sent the question later wrote he's the guy that bought the last one of those $395 X5365's at eBay I saw earlier today. (The seller had only one left unfortunately.)

Update - a reply recd on Friday:

"Yes, I've upgraded my '06 Mac Pro with two Xeon 5365s (bought from EBay for $400 each). Works great. Attached are screenshots of the About This Mac (running 10.6.1) and System Profiler screens.
-Robert"

For more complete/later info from Robert, see the October 2nd, 2009 news post on
3GHz Clovertown (Quad-Core X5365s) upgrade in a 2006 Mac Pro.

"EyeTV iPhone app and 3.2 update
Nice picture as your linked review points out, but audio is about 1/2 second out of sync! As you're doubtless aware, this spoils a movie completely.
I know you have a contact at Elgato so wonder if they've had any similar reports?
(I'll write him to ask but first have some questions - see below.-Mike) Tested so far on Mac mini, 1.6Ghz C2D, (EyeTV App notes C2D (or better) reqd for streaming server) 2 Gig's Ram, 10.6.1. I see my wife's G4 is a no no for iPhone TV serving :-(

(I asked for more details (i.e. what iPhone or Touch model he was using (as later models have faster CPU/GPU, etc.), info on wireless network speeds, etc.))
I bought an iPhone 3G last year, now my wife's, thinking it was a good excuse/reason to get a 3GS, so we've got both, and it's slightly better (but not much) on the 3GS. Both 3G & 3GS exhibit the out of sync problem.

I've also just bought a new router (our Linksys wag354 fried whilst we were away on holiday last week), an Apple Airport Extreme (802.11N) running firmware 7.4.2 (used with DSL modem).

(What media are you playing (recordings? Live TV?) - or does all playback have the problem?)
So far only Live TV sourced from Elgato's own "DTT stick", a USB DVB-T (the European MPEG2 digital broadcast video standard) receiver.

(Does recorded content (from EyeTV 3.2) have A/V sync OK if played back on the Mac?)
I have recorded a broadcast, but will need to convert it to H.264 to suit iPhone playback, so will do that & let you know tomorrow if sync is an issue with that.

BTW, since my earlier email, the A/V sync has become worse - about 2 seconds now, so it's a real turn off!
Thanks, John"

"This update improves compatibility and overall stability, and is recommended for all EyeTV users.
Snow Leopard Compatibility
EyeTV 3.2 is fully compatible with Snow Leopard. Versions 3.0 through 3.0.4 are not compatible with Snow Leopard, please update before upgrading to Snow Leopard.

Your EyeTV on your iPhone
EyeTV 3.2 adds support for EyeTV for iPhone ($4.99) which lets you watch, record, and enjoy live and recorded TV from your Mac at home, on your iPhone or iPod touch.
To enable EyeTV for iPhone, open the iPhone tab in the EyeTV Preferences.

Bug Fixes

Turbo.264 HD users can now access the Turbo custom options when exporting from EyeTV.

Fixed a crash when using the digital audio output.

Fixed missing commands in AppleScript dictionary.

Improved H.264 playback with certain channels.

Improved tuning for both DVB-S and DVB-S2 with EyeTV Sat and Terratec S7

Fix default sort order and improved channel assignments on several different channels.

Fix a problem where EyeTV Sat could not manually add DVB-S2 channels.

Reception improvements with the EyeTV DTT.

Improved localizations.

System Requirements
EyeTV 3.2 is a Universal application. It requires a Macintosh computer with built-in USB 2.0 ports, and Mac OS X 10.4.11 (Tiger) or later. We recommend Mac OS X 10.6.1 or later with all software and security updates installed."

• iPod touch: Hardware troubleshooting
• iPod nano (5th gen): Sharing recorded videos on Facebook or YouTube
• iPhone: Signal or other interference while in carrying case
• OS X v10.6: Using MS-DOS (FAT32)-formatted disks for home directories
• OS X Server v10.5, v10.6: How to cascade Software Update Servers from a central Software Update Server
• OS X Server 10.5, 10.6: Authentication methods for Podcast Producer
• Nike + iPod: Using multiple Nike + iPod sensors
• OS X v10.6: Mac 101 - The Dock, Dock Expose, and Stacks
• OS X Server: Spotlight may not find all files on a mounted file share if there are nested share points
• Xsan: Guidelines for volume expansion
• Keep your modem or router firmware up to date
• MacBook and MacBook Pro: Keyboard issues with Mac OS X v10.5
• OS X Server v10.5 or later: Windows Vista clients may be unable to join a hosted PDC