DFI 790FXB M2RSH- Review, Overclocking+SB750, Phenom 9950

Sylvanas

Diamond Member
Jan 20, 2004
3,752
0
0
Well, after my review of the MSI K9A2 Platinum here which had over 5500 views, I thought I would share my thought on my new setup involving AMDs reletively new SB750 boards- specifically the DFI 790FXB M2RSH.

First up the board is an AM2+ SB750 board- this means your current Athlon X2 AM2 CPUs will work aswell as the Phenoms and the incoming Deneb 45nm (after a Bios update). This board is also a beast, my last DFI board (Lan Party NF4 SLI-D) is still going strong in my Linux desktop did not miss a beat and so far I am getting the same impression from this new board. Now, the MSI K9A2 Platinum was an excellent board, but the SB750 brings with it faster USB performance and most importantly (for me at least :D ) better overclocking, AMD have stated a guaranteed 100-300mhz increase in OC when properly configured over that of an SB600 board (such as the K9A2 Platinum)- very nice. I will be using Watercooling in my Overclocking so be aware of that- in general water leads to lower temps and thus a higher OC most of the time. Also note this board is not an expensive board reletive to other high end boards, it was considerably cheaper than the Foxconn A79-S which is a similar SB750/790FX board, and around the price of the 790GX boards.

Lets get down to it, Here it is unpacked and ready to go note that I have installed the CPU and waterblock at this time (D-Tek Fuzion V1 with Quad Nozzle). In my opinion it is a good layout, note the Mosfets have a solid heatsink that looks like it was probably made my Thermalright- this heatsink and the NB heatsink are fastened by screws not pushpins this is essential to maintaining good contact with the PCB, also makes it easy to remove the heatsinks if need be. Also I should note its not all roses, the manual you get with this board is pretty light at that, nowhere near as much documentation as my last MSI board, the DFI manual only explains the physical components, the K9A2 Plat details the Bios settings aswell. The best resources are on the net, you can find them in a quick google search of this board.

BIOS
After a days work it was up and running Vista 64. My first intentions were to checkout the BIOS, in typical DFI fashion there is everything and the Kitchen sink thrown in. This is great for us enthusiasts as it means we can get the most out of our components as there is seldom anything left to teak. What I was pleased to see what fully adjustable CPU and NB multipliers within the Bios (non black edition CPUs only have an adjustable NB multi). This is a great leap over what we saw with the SB600 boards as many did not feature NB overclocking and if they did it was sketchy at best. This time is there and it works well, you will however need to know what the NB FID, NB DID, CPU FID, CPU DID values are and the best place for that information can be found here at Xtremesystems, see Tony's 2nd post where it is explained. Apart from that everything is as you'd expect in the BIOS, Voltage adjustments (that are in small increments) for CPU, Memory, NB, HT, PCI Frequency, A myriad of Memory clock values (will investigate them later) and temp monitoring.

Overclocking - Currently 3.4ghz/2.4NB
This is still very much a work in progress, I have only had the board a little under a week at time of me writing this so I will update with any more relevant info. Memory is on Auto timings at 5-5-5-15 800mhz. The NB is also an essential part of overclocking a Pheom, a higher NB frequency reduces the latency of the L3 cache and can lead to large performance gains, stock is 2ghz on a 9950- it is 1.8 on cheaper models.

Presently at:

3.2ghz and 2.4ghz NB Really all I have done is raise the Voltage two notches over stock, increase memory frequency to its rated 2.0v and change the multiplier to 16. This is stable in AOD which I have found to be just as good as prime95 for stability testing as with my X2 it heated it to the same temp as Prime.

1hr AOD stable
Everest benchmark 3.2ghz auto mem timings

Update1 - 3.3Ghz/ 2.4ghz NB stable pic all that was required was a slight voltage bump and NB voltage bump to around 1.33v

Update2: Latest progress, 3.4ghz 2.4ghz NB

Still testing, I upped the ACC value to +6% all cores over the previous 4% all cores and I did gain some stability in early Prime testing. So far it has not crashed and all things are rosey....fingers crossed. Very glad I have gotten to 3.4ghz. I should also note I upped Vcore to 1.44v Real (under load) which is 1.45v in Bios.

Will update as i go, very pleased so far, easy to use board, beginners need not be put off by the complex Bios, the Default values are stable and work well and it is not too difficult if all you need to do is get it running.
 

thilanliyan

Lifer
Jun 21, 2005
11,822
2,018
126
I'm having a crappy time with the 790GX chipset (I know...yours is 790FX). Both the Gigabyte (crapped out and needs to be RMAed) and now the Asus versions I have, have poor BIOS implementations...with the Asus now I can't even do a cold boot at stock settings without having to reboot for some reason (and with the Gigabyte I couldn't do a cold boot with ACC on...lol I haven't even ventured with OCing on the Asus...too scared :( ). Also I have to put some active cooling on the Asus version because the stock heatsink gets way too hot.

These 790GX boards are poorly implemented and poorly supported.
 

Sylvanas

Diamond Member
Jan 20, 2004
3,752
0
0
Sorry to hear your experiences with the 790GX Thilan29, sounds to me like complications due to poor QC at the factory with regard to proper mounting of the heatsinks. So far I have not encountered such problems with both of my 790FX boards.

I have updated the OP with my recent OC experiences, I am now up to 3.3ghz/ 2.4nb. I think it may be possible to shoot for 3.4, we will see how it goes, after I have found the limits of the CPU I will begin investigating the Memory timings. I am most interested in the two options within the Bios that are somewhat of a 'Performance Tweak: Enable' for use with quality DIMMs and what impact they have on performance as we all know Phenom is more responsive to Memory latency than overall clockspeed.
 

thilanliyan

Lifer
Jun 21, 2005
11,822
2,018
126
Yeah I'm regretting getting the 790GX boards. I'm guessing they'll get better with BIOS updates but those are few and far between. Hopefully this changes when Deneb comes out.
 

Sylvanas

Diamond Member
Jan 20, 2004
3,752
0
0
Update:

Latest progress, 3.4ghz 2.4ghz NB

Still testing, I upped the ACC value to +6% all cores over the previous 4% all cores and I did gain some stability in early Prime testing. So far it has not crashed and all things are rosey....fingers crossed. Very glad I have got to 3.4ghz. I should also note I upped Vcore to 1.44v Real (under load) which is 1.45v in Bios.
 

Rhoxed

Golden Member
Jun 23, 2007
1,051
3
81
great OC!

did you try that 9950 in the MSI board?

i am able to squeeze 3.24Ghz / 2.4Ghz NB speed out of my MSI with a 9850BE

getting a sb750 with the deneb when it comes out, will try my 9850 in there before i let loose.
 

Sylvanas

Diamond Member
Jan 20, 2004
3,752
0
0
Originally posted by: Rhoxed
great OC!

did you try that 9950 in the MSI board?

i am able to squeeze 3.24Ghz / 2.4Ghz NB speed out of my MSI with a 9850BE

getting a sb750 with the deneb when it comes out, will try my 9850 in there before i let loose.

No I didn't try the 9950 with the MSI board, would have meant taking it apart and draining the water loop again. Thats a nice OC you have on the 9850, if you end up putting it in a SB750 board you will see a difference- also good thing to know is according to XS the SB750 boards will also be allowing extra headroom for Deneb.
 

heyheybooboo

Diamond Member
Jun 29, 2007
6,278
0
0
Are you 'plowing new ground' with the NB voltage? Have you found others at 1.33v? Can you access that upper PCI slot in your rig? How those temps looking? Will I ever stop asking questions? - LOL

Thanks for leading the charge :thumbsup: I'm looking to upgrade from an MSI 790fx to the DFI but just can't pull the trigger (at least until I take care of things like food, gas and taxes ...)



 

Sylvanas

Diamond Member
Jan 20, 2004
3,752
0
0
Are you 'plowing new ground' with the NB voltage? Have you found others at 1.33v?

It is two notches above stock (I think thats 1.26) and I have found from other users experiences (mainly XS) that when running a NB of 2400mhz+ it is best to bump the NB a tad. 1.33v is still on the safe end of things from what I can gather (have not experienced anything to the contrary) but I wouldn't be going any higher.

Can you access that upper PCI slot in your rig?

I would assume so. I do not have anything in any of the PCI slots atm but none of them are obstructed, a sound card for example should fit neatly beside my 4870X2.

How those temps looking?

The Bios I am using 09/19 does not have accurate temp monitoring for the CPU. This has been corrected in a more recent Bios but I have not got round to flashing it. So, for the most part I am flying blind which if I wasn't on water I would be more concerned about- but the fact is the water keeps it more than cool enough. If anyone is intending on buying this board then I would suggest you make sure you either flash to the latest Bios before you start Ocing or contact the vendor and ask if they know what BIOS comes with the board. For air cooling it is a must to have accurate temps. However, having said that the NB temp seems accurate in all the programs I have used, that hits high 50's low 60's under load.