DFI SB750 boards, more scuttlebut.. NOW WITH DFI LINKS

[nanohead]

OK, just got some more info from Motherboard Pro (these guys are the only ones who seem to be able to tame DFI )

They confirmed for me that the LP JR 790GX-M2RS only supports the 125 Watt CPUs. This info came from DFI today. Many of us were wondering what kind of CPU load it would take, and we were looking at those PWM configurations and scratching our heads. Those slides in their preso said 120A (120 Amps, maybe to power a NY city subway car or something), must have meant 125W.

Also, it appears that the next gen of the 790FX board is supposed to be here soon, and as usual, DFI confuses everyone

The info claims that there will be 2 different models, just like there are now, but the model numbers make no sense, as both end with M2RS. There was a DK 790FX2-M2RS and a 790FX-M2RSB or some such nonsense. I didn't quite understand the nomenclature It might have been some mis info from the DFI sales department or something.

So it seems that the JR is good for 9850s and new 9950s, but that we have to wait for the big mother for the 140W CPUs

[Particle]

120A doesn't seem odd.

When I raise my voltage to 1.45V, I pull about 170W off the +12V rail at the mosfets. That's with a 9850 at under 3GHz for some testing. With average efficiency that I'd expect from a PWM solution like that, I'd bet it's delivering ~110A to the CPU at that voltage and frequency.

[nanohead]

120A doesn't seem odd.

When I raise my voltage to 1.45V, I pull about 170W off the +12V rail at the mosfets. That's with a 9850 at under 3GHz for some testing. With average efficiency that I'd expect from a PWM solution like that, I'd bet it's delivering ~110A to the CPU at that voltage and frequency.

110 Amps? Thats Arc Welder territory 110Watts is more like it!

[Particle]

Not really. When an OC'd CPU is pulling say 150W and at a voltage of 1.40V, it's pulling 107 amps. You don't have any power factor concerns with CPU power usage, as all power applied is DC. This falls into Ohm's Law[ish] territory.

Since Volts * Amps = Watts in such a scenario, you can use simple algebra to see that Watts / Volts = Amps. 150 / 1.4 = ~107. You ever wonder why there are so many power pins on a CPU? If a CPU that dropped 120W ran off of 1000VDC, you could probably get by with a single pair of pins for power. It isn't power that determines the wire size needed. It is the current. Drop resistance or increase voltage for any given load and you can use a wire with a lesser cross-section. In the case of a welder, your cables may need to be 30 feet long. The resistance of 30' of wire with so much current is why it's so large. If your cables only needed to be two inches long, you could get by with a MUCH smaller wire.

There's nothing shocking about the high current numbers.

[Morgoth Bauglir]

The info claims that there will be 2 different models, just like there are now, but the model numbers make no sense, as both end with M2RS. There was a DK 790FX2-M2RS and a 790FX-M2RSB or some such nonsense. I didn't quite understand the nomenclature It might have been some mis info from the DFI sales department or something.

UT=Ultra
LT=Light
DK=Dark
Jr.= Junior

B=B version
R=Raid 5 support
S=Solid state capacitator

The other bits are self explanatory. If DFI are still respecting their initial plan, there should be a DK 790FXB-M2RS and a UT 790FXB-M2RS, which means B variants for the current DK/UT boards. This is caused by adding SB750 (the revision), nothing else should be different from the current DK/UT incarnations (so still 4+1 phase for DK and 6+1 for UT). Of course this is DFI so roadmaps might not mean much for em.

[nanohead]

UT=Ultra
LT=Light
DK=Dark
Jr.= Junior

B=B version
R=Raid 5 support
S=Solid state capacitator

The other bits are self explanatory. If DFI are still respecting their initial plan, there should be a DK 790FXB-M2RS and a UT 790FXB-M2RS, which means B variants for the current DK/UT boards. This is caused by adding SB750 (the revision), nothing else should be different from the current DK/UT incarnations (so still 4+1 phase for DK and 6+1 for UT). Of course this is DFI so roadmaps might not mean much for em.

I was trying to discern between the higher end variant (the UT M2R) and the more practical board (the DK M2RS). But both model numbers I heard were DK and M2RS(B), leaving me to believe at least that they were maybe NOT going to do another M2R style higher end board. Not sure if they need to, not sure if I'd buy one either.

I have the M2R and don't use the Bernstein audio, the firewire or the silly transpiper (I did, but it was always in the way and not that effective) I do use the Silicon Image RAID controller though, although I might not with the SB750.

[nanohead]

Now I'm even MORE confused

Well, here are the links from DFI...

the LANPARTY DK 790FXB-M2RSH

http://us.dfi.com.tw/Product/xx_prod...P%20DK&SITE=US

And here is the other....

LANPARTY DK 790FXB-M2RS

http://us.dfi.com.tw/Product/xx_prod...P%20DK&SITE=US

What is the difference?

EDIT: I just compared, and I think its ONLY the heatpipe... on the H model. Now I'm so scratching my head

And they both have 4+1 power, neither have pure digital 6+1 like the M2R does. Huh?

[MrMojoZ]

H for Heat pipe!

[Sumanji]

Damn no UT or LT but they add another SKU for a sh1tty heatpipe going from NB to fets, WTF?!?!

But I did spot this gem...

AMD® AM2+ processors: Phenom FX / Phenom / Athlon / Sempron

[nanohead]

Damn no UT or LT but they add another SKU for a sh1tty heatpipe going from NB to fets, WTF?!?!

Yeah, WTF is right? That is an absurd design choice, I have NO idea what these guys are thinking

Not only that, but they still artificially constrict the 3rd PCIe slot to a x4, so a dopey 3 way Crossfire config from an I/O bandwidth load balancing perspective too. WTF again!!!!

Looks like they've abandoned the high end for AMD , unless there's another M2R product coming, but I've not heard anything about it. What a bummer if thats the case. I'm gonna call DFI sales tomorrow in Ca and see if anyone knows anything about an M2R with the SB750.

[SocketMan]

H for Heat pipe!

H is for How much longer?/B]


Do we have to wait.


These are the FX take 2,should support the 140w CPU's easily.

So it looks like we're getting 4 new boards from the
DFI: 2 790gx and 2 790fx which is what we were thinking for the last
X months.Good find btw Nanohead,
I just looked at their site a couple of days
ago and there was nothing there yet.

I assume that "the other gx" is still that "red" budget looking mobo is that
correct?


A composition called:Do we have enough 790's

[Daveburt714]

That first pic looks like a really interesting board SocketMan...

I'm pretty sure all of us early adopters of Phenom know how important the PWM section of the boards are. Do you have any clue as to why the power section of that board has 2 rather large IC's where the chokes would normally be?

I'm wondering if it may help steady the power/response sent to the CPU. If it does I would have to think that could be a serious help for the stability of the X4's...

I've never owned a DFI, I've read quite a bit, both good and bad, but I have to admit that design looks kind of intriguing...

[BossBorot]

the first board has a digital power deliver system that is far different from the pwm on the other boards

[Daveburt714]

the first board has a digital power deliver system that is far different from the pwm on the other boards

Thanks Boss, after a little more research, it looks like that is actually the older M2R w/sb600. Unless they used the same basic design and replaced the sb600 with the sb750 adding the lines to take advantage of ACC....

If that's the case, I would definetly be interested in that board...

[Oese]

unfortunately it IS the older m2r. the first two boards are the sb600 ones..

and answer is NO, we do not have enough 790FX.. Where is the UT with sb750..

But perhaps pwm-section simply is not as imßportant for 45nm Phenom and thats why DFI does not sport such investment in the power circuitry... This whole PWM thing is expensive i think..


Nice about the new Boards is the diagnostic led even on the m2rs's....

[nanohead]

I read the manual, and from what I can tell (which does not mean I am correct) it does indeed look like there is really only 1 board, which is the FXB series, and the heatpipe is the difference between the models. There appears to be only 1 manual for both boards.

If that is the case, then the cheapest 1 is best if you're gonna water cool everything, which I'm going to do anyway. I just hope they keep the BIOS development activity and depth like it has been, especially like it its been for the M2R. Then I'd be convinced.... right now, I'm disappointed for sure. Especially when compared to the breadth of X48 models they've done.

It looks like maybe their investment in AMD is going down, while Intel is going up. From a commercial standpoint, I can certainly understand. But its still a bummer

And BTW, that power section looks identical to the 790GX and original 790FX M2RS board, which DFI claims is only 9850 capable. What am I supposed to do with my 9950 though? I dunno

[Sumanji]

Yeah I don't mind losing the silly external heatpipe, extra giga LAN, extra Firewire etc. etc.

But using crappy 4-phase power instead of digital fets is fail Why couldn't they just update the LT/UT with SB750? Afaik SB600/SB750 are both pin compatible so it would just be a case of drop-in replacement and some small BIOS changes?

[MrMojoZ]

Even when AMD chips were faster there were still more high end boards for Intel CPUs. The current performance lag for AMD chips only makes this worse. DFI could own the high end Phenom market with a good board, lets hope they decide it is worth it.

[nanohead]

Yeah I don't mind losing the silly external heatpipe, extra giga LAN, extra Firewire etc. etc.

But using crappy 4-phase power instead of digital fets is fail Why couldn't they just update the LT/UT with SB750? Afaik SB600/SB750 are both pin compatible so it would just be a case of drop-in replacement and some small BIOS changes?

Yep, my thinking exactly. All I really care about is the power section, and rational distribution of PCIe bandwidth. I have NO idea why they do this 16/16/4 thing on the M2RS and 16/8/8 on the M2R. Makes zero sense, as the total amount of lanes in the 790FX is still 42 lanes regardless.

I hope we're not over reacting and they are gonna do a proper implementation of a better board, but I don't think so. What a bummer......

Just don't know what they're thinking is, unless the whole first gen 790FX product family taught them things we don't know

[RGone]

Only current information as I understand it as of 9/9/2008 mm/dd/yy.

LP DK 790FXB-M2RSH: Should be available in Usa.

LP DK 790FXB-M2RS: Minimal or none yet.

LP DK 790GX-M2RS: Will not "build" until end of Sept.

LP JR 790GX-M2RS: Should be available in Usa.

No word at all on UT 790FXB motherboards.

[Sumanji]

Maybe if Deneb performance is half-decent they will consider launching UT/LT boards... but for now AMD = budget lineup

[Jaivan]

Was really looking forward to a new UT 790fx. I really like the expansion slot configurations compared to the asus model M3A79-T.

I'm really tired of waiting for DFI to pull their heads out of their a$$es and update a frigging southbridge.

Guess i'll be getting an ASUS board this time around

[Rammsteiner]

w00t, so they're more or less announced now. So 1 more month to add to the 2.5 months of waiting already... We're over 50% of waiting now though.

Cant wait to get this board.

TBH, I know Ive said I wouldnt, but Im thinking to grab a 125W 9950BE anyway.

[Rammsteiner]

ETA seems to be oktober... Looks like I was even right on waiting time too prolly. Didnt expect to see anything else though from DFI, I dont care.

I know Im the first on the pre-order list so... what gives

[SocketMan]

I think they're not doing a "UT" because is costs more to make and does not
sell as well. When there are "similar" (read identical) boards come out at the same time (like M2R and M2Rs) most people buy the m2rs and DFI needs to make money.
Also I think (many would disagree ) that the M2R was an overkill
in terms of the kind of power it can handle
Besides SB600 and SB750 is "pin compatible" is it not?
Who knows maybe some one can flip the SB's and mod the BIOS, and
make it XSTREME