Originally Posted by K7Raid
I have that exact board in a build, I ended up using a E5472, had no problems whatsoever. I ended up using XFX's P10 bios. Make sure that you have the memory unlinked and within the right timing/frequency. The link to the exact bios I used is http://members.iinet.net.au/~michaeldd/790i_P10_XFX_(DELL_SLIC_v2.1).rar
I do not recall if I injected Microcode but I do not believe I did. Hope this helps.
Thanks for the suggestion,
I tried a lot of different BIOS's with no luck. The 790i is really picky about CPUs in my experience. There is more in the BIOS controlling which CPUs work other than the microcode. For example, my Pentium D 925 isn't officially supported, however it worked perfectly using an old bios (previous to P09, dont remember what version it was) and using the P10 bios. However, it would get stuck at post code 29 when I tried to boot using the P09 bios (I had to order a new BIOS chip to hot flash back to P10 on the original chip). P09 and P10 both use the same microcodes for the Pentium D 925, so that was strange. That's why I think there is more controlling cpu compatibility in the 790i bios than simply microcodes.
I picked up my E5405 for $13.00 on eBay, it wasn't a big loss so I decided to use a X5470 instead since others have confirmed that works That was only $85.00 on eBay and will be much faster than the E5405. It works perfectly on my board, although overclocking it while using 16GB of memory is difficult, I think the SPP is being pushed to its limits.
I'm going to try the E5405 in the old family desktop computer. It uses a 945GC chipset and has a single core Celeron D 360 in it right now, I added the microcodes for the E5405 to the BIOS but haven't tried it yet. I'd be nice if it worked since it will be waaaaaay faster than the Celeron. I'll post my results on that later.