Possibility of AM3+ CPUs working in AM3 boards?

[bardacuda]

There seems to be a lot of confusion about this possibility mostly because of ASUS's statement that certain existing AM3 boards will be able to support AM3+ CPUs with a BIOS update, and also the fact that JF-AMD has stated that AMD is not supporting Bulldozer in AM3 sockets. Here is a link with an interesting discussion of the topic. Keep in mind that AMD not supporting it doesn't mean it isn't technically possible.

There is also the fact that AM3+ sockets have 942 pin holes where as AM3 sockets only have 941, so there is the issue of whether an AM3+ CPU will even physically fit into an AM3 socket. However, we know that AM3 CPUs only have 938 pins, and I have not been able to find any good info on the number/placement/mapping of pins an AM3+ CPU will have. Anyone have any more insight on this?

Reason I am asking is because, like many other ppl I would imagine, I am wondering if I will be able to extend the life of my AM3 board by plugging in an AM3+ CPU down the road once they come out. Obviously it will not only depend on physical pin #/placements and such, but also if the new pins are even electrically connected to the board, even if it does fit mechanically into the socket, and also whether there will be a proper BIOS available. I know it's more than likely all wishful thinking, but maybe not considering how limited my info/understanding is on the scope of the subject at this time.

So basically I am wondering if there are any tech geniuses out there that maybe have more insight about the whole matter that could give a better idea of the technical possibility at this time.

My specific board is an MSI NF980-G65. Has anyone heard if MSI will be releasing BIOS updates for any of their AM3 boards to support AM3+? If not anyone out there with the know-how nice enough to whip one up for me? Just tell me which pins i need to rip out first and what to sodder where!

Thanks!

 

[jaquith]

Until AMD officially states AM3+ compatibility, I wouldn't bet the farm - http://en.wikipedia.org/wiki/Socket_AM3#Compatibility This came up with the LGA 1155 where some MOBO Mfg's said the Sandy Bridge would/could work {BIOS CPUID flash} on the LGA 1156 as I recall Biostar -- never saw the MOBO.

 

[bardacuda]

Until AMD officially states AM3+ compatibility, I wouldn't be the farm

Keep in mind that AMD not supporting it doesn't mean it isn't technically possible.

I know it's more than likely all wishful thinking

 

[bardacuda]

UPDATE: MSI announced today that they will be releasing BIOS updates for certain AM3 boards which will make them compatible with AM3+ CPUs. Things are looking up!

The list of boards that will compatible are:

890FXA-GD70
880GMS-E35
890FXA-GD65
870A-G54
890GXM-G65
870A-G54H
880GMA-E55
870A-G46
880GMA-E35
760GM-P33

Mine's still not there though but here's hoping!

 

[jaquith]

Good to know.

I'm only socked in that the pin limitation to keep compatibility is hurting the performance possibilities to the Bulldozer. For example the LGA 1366 has 1,366 pins and the upcoming LGA 2011 indeed has 2,011 pins; yeah it matches the release year also. The more the pins the 'more the' data I/O potential.

 

[bardacuda]

AFAIK there will be performance limitations in the sense that most AM3 boards do not support the higher memory clock or HyperTransport speeds that AM3+ CPUs will be able to support, but I can't see that having much more than a minimal impact (especially with a little bit of overclocking) except in maybe some very specific memory-intensive or some other programs that most people will never use anyway.
The other thing though is that some features may not work or be available.
From the link you posted:

Some manufacturers have announced that some of their AM3 motherboards will support AM3+ CPUs, after a simple BIOS upgrade.[9] Mechanical compatibility has been confirmed and it's possible AM3+ CPUs will work in AM3 boards, provided they can supply enough peak current. Another issue might be the use of the sideband temperature sensor interface for reading the temperature from the CPU. Also, certain power-saving features may not work, due to lack of support for rapid VCore switching.[10] Note that use of AM3+ CPUs in AM3 boards may not be officially supported by AMD.

The temperature reading/power-saving features could be an issue for some users...and like it says some boards may not be able to provide enough peak current for an AM3+ CPU which I guess means that maybe only 95W or lower AM3+ CPUs (or none at all) will be able to be used depending on the board and it's power limitations.

All that said though, I would be happy to forego those features to be able to drop in a Bulldozer chip and keep my 3-way SLI capable mobo that I just dropped $150 on not long ago, instead of having to either upgrade the mobo, or be left with only the option of a sideways upgrade from my Athlon II X4 to a Phenom II X6...especially if the new processors are on par with Sandy Bridge.

 

[kilo_17]

If this is true............I hope MSI releases BIOS for AM3+ support for the 880GM-E41. This is a touchy subject, seems like nobody quite knows whether or not BD can be dropped in an AM3 board.

 

[bardacuda]

If this is true............I hope MSI releases BIOS for AM3+ support for the 880GM-E41. This is a touchy subject, seems like nobody quite knows whether or not BD can be dropped in an AM3 board.

Yeah that's why I made this thread...I was hoping someone more enlightened would see it that could shed some more light on the situation and enlighten the rest of us. Anyway though it seems like mechanical connectivity as an issue can be eliminated, and paired with this announcement I'd say things are looking up.....so that's good news! Still though I'm sure there a LOT of AM3 board owners that haven't had their boards mentioned on any particular board maker's official supported list that are just DYING to know if theirs will end up being compatible...self included!

 

[kilo_17]

The bad thing though, I have a feeling that BD running in an AM3 board will probably hold back some of it's potential. And what if AMD doesn't officially support it, which could mean if you decide to drop a BD proc into an AM3 board, it might void your warranty, you know?

 

[bardacuda]

The bad thing though, I have a feeling that BD running in an AM3 board will probably hold back some of it's potential. And what if AMD doesn't officially support it, which could mean if you decide to drop a BD proc into an AM3 board, it might void your warranty, you know?

That's not an issue in my case since I've already voided my board's and CPUs warranties by overclocking, and as long as the potential is a good chunk better than a Phenom II X6 I'll be more than satisfied.

 

[kilo_17]

Speaking of that, did you get a performance boost by OCing your X4. I have the same proc and was just wondering, as it's more than enough for me. Anyway, you have a good point, BD will outperform AMD's current offerings I would think, so AM3 or AM3+ you're still probably bound to get better performance.

 

[bardacuda]

Speaking of that, did you get a performance boost by OCing your X4. I have the same proc and was just wondering, as it's more than enough for me. Anyway, you have a good point, BD will outperform AMD's current offerings I would think, so AM3 or AM3+ you're still probably bound to get better performance.

I really can't tell since the first thing I did when I built the system was overclock it. I don't have the GPU setup yet to max out this CPU at stock anyway and don't do any major encoding or anything that would really give me any indication of it's upper limits at stock or otherwise.
Only thing I can tell you is that with it's overclock to 3.58GHz it gets 45 GFlops in linX with the 4GB memory @ 1644 8-8-8-24 1T, the NB @ 2713MHz, and HTT @ 2220MHz. Maybe run linX on yours at stock and see what you get as a comparison. It really doesn't matter obviously if you're just browsing/e-mailing. I put Cool n' Quiet back on once I finished OCing so right now it's running at 980MHz @ 1.08V and surfing on my browser is plenty fast enough at that speed.

 

[kilo_17]

Ah, neat. I don't have mine OCed simply beacuse it handles everything I need it for, lol if I had like a 2500k or something I probably would do it just to say I hit 4ghz or something. I'm just wondering, but does your board have an Nvidia chipset?

 

[bardacuda]

yup it's the nForce 980 chipset

 

[kilo_17]

That makes me wonder, what if AM3+ support is limited to boards with AMD chipsets? Not saying that it's true, just makes me think a little bit.........

 

[bardacuda]

That makes me wonder, what if AM3+ support is limited to boards with AMD chipsets? Not saying that it's true, just makes me think a little bit.........

Maybe not for current AM3 boards (hope that's not the case), but there will be new AM3+ boards with SLI support....but I guess they are still AMD chipsets?? I dunno I'm confused now.

Nvidia to Offer SLI Support for AMD 900-Series AM3+ Bulldozer Motherboards

Then again an AM3+ CPU isn't supported (by AMD at least) on any AM3 boards anyway.

 

[badoosh]

I am pretty sure AMD will release a driver or bios update for their AMD chipsets to allow you to use a AM3+ CPU on a AM3 socket but I maybe wrong too or just like the AM2+ socket you can use an AM3 CPU but I guess we will all have to wait and see!

 

[bardacuda]

I am pretty sure AMD will release a driver or bios update for their AMD chipsets to allow you to use a AM3+ CPU on a AM3 socket but I maybe wrong too or just like the AM2+ socket you can use an AM3 CPU but I guess we will all have to wait and see!

Well right now it looks like AMD isn't supporting it at all and it's going to be up to the board makers if they want to support it or not, but like ya say we pretty much just have to wait and see.

 

[kilo_17]

I was talking about whether or not AM3+ CPU support would be limited to current AM3 boards with AMD chipsets. Like I said, it's just a thought, but it kinda makes me think.......

 

[kilo_17]

Yep, if a certain company would give us some info or just release it already, we could go from there and see if BD works with AM3. :lol:

 

[bardacuda]

I was talking about whether or not AM3+ CPU support would be limited to current AM3 boards with AMD chipsets. Like I said, it's just a thought, but it kinda makes me think.......

Well I'm glad you said it, cuz if you said you were sure it will be supported on nVidia chipsets I'd have to accuse you of jinxing me! lol

 

[kilo_17]

Ha! Guess we'll find out soon! Don't get me wrong, I'm not saying it will work on AM3 boards with nVidia chipsets, I'm not saying it won't, it was just a thought that popped into my head. Heck, nobody's even sure BD will work on AM3 at all! Too bad all we can do about it is wait and see.

 

[bardacuda]

Ha! Guess we'll find out soon! Don't get me wrong, I'm not saying it will work on AM3 boards with nVidia chipsets, I'm not saying it won't, it was just a thought that popped into my head. Heck, nobody's even sure BD will work on AM3 at all! Too bad all we can do about it is wait and see.

Well I think it's safe to say that it will work in the ones ASUS and MSI have announced as being compatible, otherwise they would have a bunch of pissed off customers and RMAs on their hands.

 

[jaquith]

CPU Pins, again, it had me thinking a little more. I couldn't help but notice the relation to 'speed and performance' to the increasing number of pins. http://en.wikipedia.org/wiki/CPU_socket

I guess I was hoping more like the Magny-Cours with it's G34 1944 pin design, etc. I did note the native 1866 MHz DDR3 and it's better approach to HT.

Example, the SB has moved the PCIe off from the 'P55, X58, etc' on to the CPU to eliminate latency. The LGA 1155 with it's 20 and LGA 2011 has 40. To some degree that does and doesn't require additional pins, but the Quad-Channel DDR3 with 256-bit wide memory interface does require additional pins.

I have no doubt that the I/O is considerably faster with the Bulldozer, however backwards compatibility also means no or limited new functions other than internally. I want to have high hopes for the Bulldozer -- I tend to gravitate towards the 'fastest' CPU with overall performance irrespective of whose 'it' is and to some degree costs for Desktops.

I was happy to see the Article you linked "Nvidia to Offer SLI Support for AMD 900-Series AM3+ ..." -- currently even with the HD 6990 I'm an nVidia guy though the AMD has been making good progress with their GPU designs; they still need to improve efficiency to decrease temps.

 

[kilo_17]

So you think that AM3 would hold back some of BD's potential?