AM3+ motherboard choices.

Hello people. I am upgrading my current system and have settled on purchasing an FX8320. However, I am trying to be as cost effective as possible so am looking at sub 100 pound motherboards I can use for overclocking in 4.5GHz range (or higher). I have already selected an adequately large HSF for the task so am now focusing on the motherboard.

Currently I'm looking at the Asus M5A97 EVO R2.0 (6+2 phase) and the GA-990xa-UD3 (8+2 phase) as my choices. I am not interested in Crossfire performance and am leaning towards the ASUS board currently, as it is cheaper and some are suggesting its 6+2 VRM implementation could be better than the Gigabyte 8+2 phase implementation. If anyone has any suggestions as to which choice to make or if there is a completely different board I should pick please feel free to chime in.

M5a99x evo

Thanks for the suggestion Flank3r. I do have to ask one question though, given that both the m5a97 evo and the m5a99x evo have a 6+2 phase VRM and very similar heatsinks, what advantage does the m5a99x have? It's about 30 pounds more expensive.

There are a limited number of AM3+ mobos with a properly designed VRM circuit to power an 8-core FX processor - regardless of what some mobo makers claim.

Specifically the only Gigabyte mobos that have a VRM circuit that won't overheat when you run an 8-core FX processor hard is the "FXA" series which was just recently released. Gigabyte has known for over two years that the other models they were selling would constantly overheat the VRM circuit with 8-core FX CPUs and reduce the CPU frequency and voltage to cool the VRM circuit which was never designed to handle the power that an 8-core FX CPU requires.

The number of phases in the VRM circuit is only part of the story. More phases tends to reduce voltage ripple which is good. The number of phases however does not guarantee that the circuit design uses the correct components to supply sufficient electrical power. More phases with plenty of power is the goal for power hungry 8-core FX CPUs.

I've used all the major mobo brands. I'm not a fan of Asus as the only two mobos that I have had fail in 20 years of building PCs were Asus. They use multiple companies to manufacture their mobos so you never know what you're going to get. Their tech support tried to give me a POS hand solder repaired mobo to replace a like new 2 month old mobo that died. I returned it and bought a new Gigabyte mobo and never looked back. Their tech support like Gigabyte's is just laughable. In many cases you can get better tech support from the forums than from either Asus or Gigabyte tech support, IME.

Make sure that whatever you buy properly supports the FX-8000 series CPUs and has the PCIe slots, etc. that you need.

Yeah I had heard that about the Gigabyte motherboards. I'm quite set on the ASUS one since the retailer I'm going to get it off has a favourable returns policy and is in driving distance, so when I've had stuff break I just pop it straight back to them. At this point I'm now wondering the difference between the 990 and the 970 version, given that I'm only interested in the VRMs and not the USB/SATA/PCI-E slots.

As far as Asus vs Gigabyte, I'm sure you'll find opinions that go both ways... ;)
Personally, I gave up on GBT a few years ago after a number of problems ranging from poor bios to overheating vrm and throttling.

As for the M5A99/97 R2.0 question, I can only speak for the 97 variant. I had that board and tested it with an 8350 that was Prime stable @ ~4.7 on an Asus Sabertooth. With the M5A97 R2 it maxed out ~4.5 stable. If you get a decent chip and will be happy with 4.5 the 97 should get you there.

If you want to push harder, Flank3r has tested a LOT of hardware, so there's probably a reason he suggested the 990fx... :D
I know you said you were on limited budget, but if you plan to explore the limits of OC'ing (and can afford it), I'd say go one step farther and look at the Sabertooth.

The ASRock EX9 is also a very capable board and a little cheaper, but requires a little more fiddling and isn't as OC friendly as the Asus boards...
That being said, if your willing to invest the time time the EX9 can hang with the big dogs! :yepp:

The difference in 970 vs. 990 chipsets in mostly the PCIe lanes for use with Crossfire.

http://en.wikipedia.org/wiki/AMD_900_chipset_series

The Asrock E9 is a very capable mobo but it's more expensive than the Asus M5A97 EVO R2.0. It has the 12+2 phase VRM and even supports the FX-9000 series CPUs if you ever intend to run one or do extreme overclocking.

I have an Asrock Fatality Pro and an FX-8350 that runs 24/7 @ 4.6 GHz. and will run 4.7+ GHz. if I want to up the vcore higher. I have run 3x, 25 hour P95 durability stress tests without a single error or overheating...

The Asrock E9 is the successor to the Fatality Pro without some of the extras. The new Asrock Fatality "Killer" (dumb name), is an 8+2 phase VRM design and it supports the FX 8-core CPUs without issue. The Killer is closer in price to the Asus mobos and less than the Asrock E9. IME the Asrock highend mobos OC as good or better than the Asus and Gigabyte highend mobos.

These Asrock's are all quality mobos and Asrock customer support is by miles the best I have seen from any of the Asian mobo makers.