Roundup: Four 790FX Socket AM3 Motherboards

Name: Roundup: Four 790FX Socket AM3 Motherboards
Author: Thomas Soderstrom

by Thomas Soderstrom April 22, 2009 at 1:00 AM

More than just a relic of AMD’s original Spider platform, the 790FX remains the company's only real enthusiast northbridge. The newer SB750 southbridge offers modern peripheral performance too, while DDR3 support via AMD’s latest on-die memory controller is the latest performance trend.

The big reason you'd choose a 790FX over the more “modern” 790GX is its 38 PCI Express (PCIe) 2.0 pathways, which can be configured as two x16, four x8, or a mix of single x16 and two x8 sets, with six pathways to spare. As with the 790GX, AMD’s third-generation HyperTransport interconnect links the 790FX to the AM3 processor, so the only two things more “modern” about the 790GX are its onboard Radeon HD 3300-series graphics core, which enthusiasts don’t want anyway, and its release date.

We have to suspect that most AMD enthusiasts haven’t considered shifting over to AM3 yet because of the lack of top-range clock speeds for DDR3-supporting processors (plus the fact that half are triple-core models, while the other half are quad-cores with cut-back cache).

AMD will release updated models soon, but we can’t give you the speed or the date (Ed.: Here's a hint: check back tomorrow). Until then, many are choosing the Phenom II X3 720 Black Edition for its excellent reputation in overclocking, since most programs can’t take advantage of all four cores of the slower-clocked Phenom II X4 910.

Socket AM3 Processors
Model	Frequency	L3 Cache	Voltage	Model #	Socket
Phenom II X4 910	2.6 GHz	6 MB	0.875-1.425V	Tray: HDX910WFK4DGI	AM3, AM2+, AM2
Phenom II X4 810	2.6 GHz	4 MB	0.875-1.425V	Tray: HDX810WFK4FGI; PIB: HDX810WFGIBOX	AM3, AM2+, AM2
Phenom II X4 805	2.5 GHz	4 MB	0.875-1.425V	Tray: HDX805WFK4FGI	AM3, AM2+, AM2
Phenom II X3 720 BE	2.8 GHz	6 MB	0.850-1.425V	Tray: HDZ720WFK3DGI; PIB: HDZ720WFGIBOX	AM3, AM2+, AM2
Phenom II X3 710	2.6 GHz	6 MB	0.875-1.425V	Tray: HDX710WFK3DGI; PIB: HDX710WFGIBOX	AM3, AM2+, AM2

Summary

About the author

Thomas Soderstrom @hardware_tom

Thomas Soderstrom is a Senior Staff Editor at Tom's Hardware US. He tests and reviews cases, cooling, memory and motherboards.

Ask a Category Expert

Create a new thread in the US Reviews comments forum about this subject

Title
Subject
Title

This thread is closed for comments

38 comments

Comment from the forums

Your comment

Anonymous 9 years ago

i like that dial on the MSI... mmm.
NitroSuperSonic 9 years ago

AMD Phenom II X3 720 Black Edition
(2.80 GHz, 86.0 MB Cache)

I never knew any AMD processors had that much cache!
judeh101 9 years ago

NitroSuperSonicAMD Phenom II X3 720 Black Edition(2.80 GHz, 86.0 MB Cache)I never knew any AMD processors had that much cache!

Super CPU!
ifko_pifko 9 years ago

"Asus has clear performance leadership,..." :-)))
1.66% better than the worst performer in the tests. :-)
tacoslave 9 years ago

who said Phenom II has low cache size i think with those 86mb you can do amazing things!!
tacoslave 9 years ago

sorry about the double post but i would have liked to have seen these benchmarked with two 4870x2's... since they keep talking about them so much.
cangelini 9 years ago

Super CPU fixed

Not much point in throwing that much GPU horsepower at a motherboard review; the card Thomas used is our current reference--and it's more than ample for showcasing the differences between these boards.

If you want to see quad-CrossFire for any specific reason, feel free to let us know and we can put together a story idea!
EQPlayer 9 years ago

I think people would like to see a dual-295/dual-4870x2 series of benches if only for the "OMG BEASTLY!" factor. I dunno. XD
Crashman 9 years ago

ifko_pifko"Asus has clear performance leadership,..." :-)))1.66% better than the worst performer in the tests. :-)

Consistent would have been better if not for the fear of people pointing out ever tiny inconsistency. Just remember, if you're 5'11" tall it's clear to just about everyone that you're not 6'!!!
Proximon 9 years ago

cangelini...the card Thomas used is our current reference--and it's more than ample for showcasing the differences between these boards.

Could you clarify that a bit Chris? Are you saying you would not expect any difference in crossfire between the MBs? If so, that's OK. However, if there's going to be a difference, that is the main reason to buy a 790FX. If you aren't going to crossfire might as well get a GX.

I suspect the chipset isn't the whole story and the various manufacturers could still screw up the PCI-E voltages or something
cangelini 9 years ago

Prox,

It depends on the numbers you're looking for. I interpreted the OP's request to mean he wanted performance results with 4870 X2s, which are overkill for comparing these boards. If it's a matter of comparing PCI Express scaling (the reason for going FX instead of GX), check out this piece: http://www.tomshardware.com/reviews/crossfire-pci-express,2095.html. It isn't on the AMD platforms, but it still illustrates fairly well how much/little performance you'd lose with PCIe 2.0 x8 vs. x16.
wira020 9 years ago

i think comparing dual gpu and single gpu would be a great idea... there could be inconsistency between the motherboards at crossfire setting... i mean u did test using 2 ram and 4 ram rite... and there's a difference in performance... hope this makes sense.. and yeah it's also bout the beastly impact and stuff...
SpadeM 9 years ago

I think that a quad crossfire would be of interest to a motherboard review. Just to answer questions like: Are two 4870X2 better then 4 x 4870 or 4890 or 4850? Does the PCIe pathways bottleneck (if it happens) the GPUs when running in 8x mode? How about the stability of the system with 4 physical cards instead of 2 or just 1 ... and so on.

Granted my request isn't based on the real needs of the consumer, it's more of a scientific curiosity behind it. But I remember a while back tom's had an article about nvidia's SLI with 2, 3 or 4 cards in different configurations and that was an interesting read.

PS: Just to clear something up in the 2 x 4870X2 vs. 4 x 4870 or other versions. I know that 4x4870 are more $$ then 2x4870X2 but if you buy a 4 slot PCIe motherboard what if you start out with a single 4870 or 4890 and just add in cards over the period of a year since prices change and people might not have all the cash to get 4 cards at the same time.
coolgod 9 years ago

phenom ii out for testing tomorrow we hope
EQPlayer 9 years ago

The Editor's Note kinda confirms that theory, yeah.
Anonymous 9 years ago

They are using a 260 for the video card. Will these boards SLI as well as Crossfire?
curnel_D 9 years ago

Lol, basically these guys want an article that would have taken another day or two to write, and a thick stack of video cards so they could see the performance differences between 2x 4870X2's, 4x 4870's, and then perhaps any combination of 4870's and an 8800gt thrown in the mix for physiX. :P
sublifer 9 years ago

To avoid confusion with the AM2+ based 790FX boards they ought to call it 793FX or something different...
monkeysweat 9 years ago

I just question why you would buy a board for AMD's spider platform,,then use a Nvidia product?? seems kinda weird to me,, if i was buying something "high end", I'm not going to buy an accessory whether it works properly or not from a competitor to complement it. I would have liked to at least see the comparison using AMD products.
SpadeM 9 years ago

cangeliniIf you want to see quad-CrossFire for any specific reason, feel free to let us know and we can put together a story idea!

"We guys" just made a suggestion since Chris stated he's opened to ideas. The asrock X58 article a few days back is another good example of a story that can be looked at from a more technical perspective. Since that board and these two AMD ones share 4 PCIe ports and ATI & Nvidia cards support ATI STREA/CUDA one would be inclined to have a look beyond the "can it run crysis" comment. And I'm sure finding 4 identical cards isn't an issues since the time that takes to right an article wasn't up for debate.