AMD FX Zambezi Processors Compatible with ASUS AM3 Motherboards Using BIOS Update

[HalfAHertz]

Didn't we already have this discussion at lengths with LGA 1155? Excessive backwards compatibility is a double edged sword. If it works - great you won yourself a few more customers, but if it compromises performance or if the time and money needed to make it work are greater than those sales, then it's time to move on.

 

[wiak]

seems the motherboard vendors are getting ready for bulldozer lift off

 

[HalfAHertz]

Expect leak in 5...4....3....

 

[Lionheart]

Gotta Love AMD for their support....^_^

 

[Mussels]

good, so its following the same setup so far - new CPU's can work a generation back on mobos, but old CPU's wont work on new boards.


i wonder if they ditched the DDR2 controller completely?

 

[Mads321]

Let me see if I can fix this (if anyone is still reading)..

First have a look at the difference of AM3 and AM3+

Which in fact does make it physically impossible for a AM3+ CPU, to fit in a AM3 motherboard.

However, current AMD chipsets like the 890, 880, 870, 790, 760- series etc. IS compatible with Zambezi/Bulldozer/FX AM3+ CPU's.

So, what the motherboard manufacturers are currently doing, is fitting AM3+ sockets on existing AM3 motherboards, and calling them a new revision.

To sum up: For a motherboard to support Zambezi/Bulldozer/FX, it will need a AM3+ socket, but not (necceseraly) the new 990FX / 990X chipset.

Generally AM3+ sockets are black, and AM3 sockets are white, so it's actually quite easy to spot which boards are compatible, and which are not.

Just have a look at Gigabytes website, and you'll be able to spot both AM3 and AM3+ sockets on motherboards (confusingly) under the AM3 tab:

http://gigabyte.com/products/list.aspx?s=42&jid=10&p=2&v=2


If you want to check if you board has an AM3+ socket, just look for 3 things:

1) Black socket
2) Written "AM3b" in it
3) Has one less pinhole

 

[dezz]

They said it wouldn't work with the older socket because the older socket couldn't handle all the capabilities of the new architecture. If adding a single pin is the only change to the socket, and that is all that is preventing it from working on the older socket [...]

Sure it's only a pin? What if they sliced the power plane of the cores and/or the NB/L3? This way they could deliver different voltages to more parts of the new chips. AM3 CPU's could be supported by simply setting the appropriate power planes to the same voltage. Also, an AM3+ CPU could work in an AM3 board, but only with restrictions. Possibly AMD thought it's too much of a compromise. Or, it's perhaps not fully orderly from the engineers point of view.

754 to 939 was an actual change in the chip architecture.

The microarchitecture was the same, but 754 has a single channel and 939 has a dual channel memory interface.

No excuse for 939 to AM2.

??? What about 939 being DDR and AM2 being DDR2? The change of socket was necessary.

 

[Mussels]

??? What about 939 being DDR and AM2 being DDR2? The change of socket was necessary.

you forgot AM2+ -> AM3, same socket, different ram. you can run AM3 CPU's in AM2+ boards without issue.




the fact is we dont know how they're doing this, until the chips actually come out.

 

[erocker]

Which in fact does make it physically impossible for a AM3+ CPU, to fit in a AM3 motherboard.

Unless some Bulldozer CPU's don't have that pin. We don't know that right now. Perhaps that could be the difference for the different box art for the same model Bulldozer CPU's?

I'm curious as to what benefits the new chipset will bring as the memory controller is in the CPU.

 

[Jack Doph]

Perhaps we're all getting a little impatient for this release, as the speculation is rife around the web about this exact point.

Patience is a virtue .. if it didn't take so friggin long!

 

[dezz]

but old CPU's wont work on new boards.

AM3 CPU's work on AM3+ mobo's.

i wonder if they ditched the DDR2 controller completely?

Most probably.

you forgot AM2+ -> AM3, same socket, different ram. you can run AM3 CPU's in AM2+ boards without issue.

DDR2 and DDR3 standards are much closer to each other than DDR and DDR2.

 

[TheMailMan78]

Whatever happens I just don't want Gary to be right.

 

[scope54]

Unless some Bulldozer CPU's don't have that pin. We don't know that right now. Perhaps that could be the difference for the different box art for the same model Bulldozer CPU's?

I'm curious as to what benefits the new chipset will bring as the memory controller is in the CPU.

I recently took an AMD insights survey about which box excited me more, so its going to be one or the other (i assume). I picked the one that looked like AMD's logo.

 

[newtekie1]

Sure it's only a pin? What if they sliced the power plane of the cores and/or the NB/L3? This way they could deliver different voltages to more parts of the new chips. AM3 CPU's could be supported by simply setting the appropriate power planes to the same voltage. Also, an AM3 CPU could work in an AM3 board, but only with restrictions. Possibly AMD thought it's too much of a compromise. Or, it's perhaps not fully orderly from the engineers point of view.

You aren't following. He said that the socket was what wasn't compatible. Well the only change in the socket was a single pin.

My point was that if the CPU was actually incompatible, then what ASUS is doing wouldn't be possible. But in reality, the CPUs obviously work in in AM3 boards, AMD just decided to not allow them to be used in AM3 boards. AMD added a pin so that AM3+ processors couldn't be put in AM3 boards. They did a similar thing with AM2 to AM3, they removed a pin from the AM3 socket/processors so that an AM3 processor could still be put in an AM2 motherboard, but the extra pin on AM2 processors would prevent them from being put in AM3 moherboards. These pins are never actually used for anything.

I would't be surprised if ASUS is expecting people to remove that extra pin, which I can almost guarantee is unused.

 

[Tomisw]

the bios is on the air now, you can download it from asus website right now
but if you have a am3 processor (no comment about this) better don´t flash it because it may not boot

http://event.asus.com/2011/mb/AM3_PLUS_Ready/

i don´t understand, it looks like you can put on this motherboards am3+ processors right now but HOW?

 

[dezz]

He said that the socket was what wasn't compatible. Well the only change in the socket was a single pin.

A platform is not only a socket, but the electronics behind it. The difference is only a pin on the socket, but there can be differences in the electronics, too. That's what I tried to tell you.

My point was that if the CPU was actually incompatible, then what ASUS is doing wouldn't be possible.

That's right.

But in reality, the CPUs obviously work in in AM3 boards

Probably only with compromises...

AMD just decided to not allow them to be used in AM3 boards. AMD added a pin so that AM3+ processors couldn't be put in AM3 boards.

Perhaps not without technical reasons. Like I said, power planes, etc.

They did a similar thing with AM2 to AM3, they removed a pin from the AM3 socket/processors so that an AM3 processor could still be put in an AM2 motherboard, but the extra pin on AM2 processors would prevent them from being put in AM3 moherboards. These pins are never actually used for anything.

But AM2 CPU's has had only a DDR2 controller, so they coudn't even work with the DDR3 memories on AM3 boards!

 

[devguy]

??? What about 939 being DDR and AM2 being DDR2? The change of socket was necessary.

I do wonder why AMD didn't attempt to put both a DDR1 and DDR2 controller on AM2 CPUs, in order to make the 939 motherboards forwards compatible? The only thing I can think of is that when they were back at the 1.3um - 90nm die sizes, they didn't have the space luxury that the 45nm AM3 CPUs afforded them.

On the other hand, they could've tried with the 65nm Brisbane's, as that shrink brought about quite a bit of extra space, a loss of L2 cache, and a slight drop in performance over the Windsor.

Either way, the s754 -> s939 upgrade was completely necessary (no avoiding it whatsoever). On the other hand, I bet if Intel really tried, they could have made the lga1155 processors compatible on the lga1156 (not in their current state, but only if they had forwards compatibility in mind at the beginning).

 

[dezz]

I do wonder why AMD didn't attempt to put both a DDR1 and DDR2 controller on AM2 CPUs, in order to make the 939 motherboards forwards compatible? The only thing I can think of is that when they were back at the 1.3um - 90nm die sizes, they didn't have the space luxury that the 45nm AM3 CPUs afforded them.

AM3 CPU's has really one IMC that is capable of working in DDR2 and DDR3 modes, as well. There is probably too much difference between DDR1 and DDR2 to allow for a similar approach. Perhaps it's because of the voltages: DDR ~2.5V, DDR2 ~1.8V, DDR3 ~1.5V.

On the other hand, I bet if Intel really tried, they could have made the lga1155 processors compatible on the lga1156 (not in their current state, but only if they had forwards compatibility in mind at the beginning).

Sure.

 

[LAN_deRf_HA]

the bios is on the air now, you can download it from asus website right now
but if you have a am3 processor (no comment about this) better don´t flash it because it may not boot

http://event.asus.com/2011/mb/AM3_PLUS_Ready/

i don´t understand, it looks like you can put on this motherboards am3+ processors right now but HOW?

Then how are you supposed to flash it? It won't boot with an am3+ chip either until it's flashed.

 

[Mussels]

Then how are you supposed to flash it? It won't boot with an am3+ chip either until it's flashed.

new boards will come with the new BIOS, old boards its assumed you already have one of the older CPU's. This is not unique here, look at socket 775 between the generations...


edit: on topic, i just checked out gigabytes website. they've released a new revision of my board (3.1) which has AM3+ support. no mention of BIOS updated support yet.

 

[LAN_deRf_HA]

Huh? Did you read the post I was responding to? He said don't flash if have an am3 cpu, and obviously you can't flash an old board with an am3+ either. It doesn't support it until flashed... I'm assuming he misspoke.

 

[Deleted member 67555]

Unless some Bulldozer CPU's don't have that pin. We don't know that right now. Perhaps that could be the difference for the different box art for the same model Bulldozer CPU's?

I'm curious as to what benefits the new chipset will bring as the memory controller is in the CPU.

That extra pin may not come into play on this series of CPU's.....aren't the future lines to have a built in GPU....

OH and I just updated my MSI bios I went from A.80 to B.A0....Now I gotta go find out what the update was

 

[Meizuman]

Would love to try, just for kicks to drill two holes to AM2 socket and one hole to AM3 and then drop some AM3b processor and see what happens

 

[dezz]

He said don't flash if have an am3 cpu, and obviously you can't flash an old board with an am3 either. It doesn't support it until flashed...

1. Boot with an AM3 CPU installed.
2. Flash the new BIOS.
(3. Switch the thing off.)
4. Remove the old CPU.
5. Install the new AM3+ CPU.
6. Boot your AM3+ CPU equipped AM3 board.
7. Study what compomises this all means, like if the Turbo CORE works or not, etc.

UPDATE: I think ASUS updated the linked page, the text about not booting with old CPU is missing, it now reads:
"** Current BIOS update is a beta release. Please check the ASUS support site for continual updates."

 

[HossHuge]

Here's the actual press release for those who may think this is BS.

http://event.asus.com/2011/mb/AM3_PLUS_Ready/