AMD AM2+ compatibility with AM3 for how long?

[Kumagoro]

I am in the process of a very slow build for a friend as I cant decide what to get for him CPU wise.

At the mo he wont be taking advantage of quad core so its a cheapish dual core for now with
upgrading possibilities in a few years.

My first instinct was E5200 with an ok OC'ing mobo. However will intel be releasing 32 nm chips
for LGA775, past experience would show that generally the mobos are not good for new smaller
feature size CPUs. i.e. P965 boards can but are not really suited to using 45 nm chips.

Seeing as AMD's AM3 chips are supposed to be backwards compatible with AM2+ boards I wondered
if perhaps an AMD system would be better for cheaper more significant CPU upgrades. How many die
shrinks will a typical AM2+ board be good for... just down to 32 nm or if even that?

[Blaineoliver]

AM3 chips will be backwards compatible with AM2 boards, AM2 cpus are not compatible with AM3 cpus, for best middle ground a good AM2+ mobo will be fine for whatever upgrade.

[Kumagoro]

My question is how many generations of AM3 people think will be compatible with todays AM2+

[CAT-THE-FIFTH]

I am in the process of a very slow build for a friend as I cant decide what to get for him CPU wise.

At the mo he wont be taking advantage of quad core so its a cheapish dual core for now with
upgrading possibilities in a few years.

My first instinct was E5200 with an ok OC'ing mobo. However will intel be releasing 32 nm chips
for LGA775, past experience would show that generally the mobos are not good for new smaller
feature size CPUs. i.e. P965 boards can but are not really suited to using 45 nm chips.

Seeing as AMD's AM3 chips are supposed to be backwards compatible with AM2+ boards I wondered
if perhaps an AMD system would be better for cheaper more significant CPU upgrades. How many die
shrinks will a typical AM2+ board be good for... just down to 32 nm or if even that?

Intel will only be making 32nm Core i5(socket LGA1156) and Core i7(socket 1366) processors. The AM3 processors have both a DDR2 and DDR3 memory controller in the CPU so this is why they can be used in both socket AM2+ and AM3 motherboards.

[staffsMike]

I'd probably choose an AMD setup for most PC's at the moment. It's true they aren't doing anything amazing but they are giving solid upgrade paths and their chips are doing enough to keep the bulk of people happy.. if they would just buy them! lol

If the upgrade path isn't quite as good as we hope you shouldn't be any worse off with an AMD over a s775 imo.

[Pob255]

We seem to be approaching a bit of an odd junction atm in future upgrades

As CAT said the new intel 32nm cpu's are going to be new sockets, not just that but the low end/cost ones will be a separate socket from the high end ones so new motherboard will be needed.
This is going to serverly limit upgrade potential.

When with amd the early new cpu's will be cross compatible, how low it will be until the next amd socket cpu comes out . . . we'll have to wait and see.

However nether would out me off getting a socket 775 or amd2+ motherboard and a low end cpu with an eye for future upgrade.
The simple reason is that the current dual core cpu's are plenty powerfull for the majority of computer use atm and if you do start to struggle you know that you can upgrade to a range of quad core cpu's because they are out now.

Even from your given example if you had a 965 chipset motherboard while you couldn't use the 45nm you can still use a q6600
The other factor to consider is overclocking, as near enough every c2d and c2q can get .5ghz Without issue or difficulity and more with some work that gives them another area to extend there life.

[Kumagoro]

I am leaning towards intel.

At the end of the day the point of going with AMD would be that the CPU's in three years time
are more powerful (including Ocing ability) than what you can get with intel now.

Seeing as intel are

1) More overclockable,
2) Currently more efficient clock for clock
3) intel quads are more prevalent now, meaning there will be more intels cheap on ebay in a few years,

means they would be the ones to go for right here and now, especially as I read somewhere that
intel will be making core2's till 2011.

Its a shame as I wanted to put some money in the pockets of AMD but seeing as there is no
clue as to how many generations of AM3 will be backwards compatible with AM2+ I feel the risk
is not worth it. That is unless someone can find some news from AMD about their plans for that
sort of thing.

[CAT-THE-FIFTH]

Socket AM3 is coming out next month as far as I know. The thing is that for gaming the Phenom II actually does much better than most people think and it can overclock reasonably well:

http://techreport.com/articles.x/16147/4

http://www.guru3d.com/article/amd-ph...review-test/21

Comparing clock fo clock is not really valid as it depends on how much a CPU costs. The Phenom II 940 is under £190 and a Q9400 is around the same price. The Phenom II 940 is better in most games when both processors are compared at stock. The AMD motherboards also tend to be better specced for the price too. You can a 790GX motherboard for under £90. Many reviews have got the 940 to at least 3.5ghz. Overclcoking may even be possible on a much cheaper 780G as the 940 has an unlocked multiplier.

I have a Q6600 of a later batch and it needs a high voltage to reach 3ghz(or higher) than earlier Q6600 processors. Also the 45nm Intel quads do not like higher voltage unlike their older counterparts as it has lead to major problems. Anyway overclocking is not always a given so no one should ever entirely base their decision on this in case you get a bad example of e CPU.

By the time a 3ghz to 3.5ghz Core2 quad or Phenom II starts to be a major limitation it will be the time you will need to upgrade to a newer CPU architecture. Another 500mhz is not going to make a massive difference in the end IMHO. Either way if you really want to have a processor which will last longer it would be better to get a Core i7 system.

[speedking34]

I'd be careful when chosing the motherboard manufacturer though. I know that only a couple of them released BIOS upgrade (including ASUS) to make their product AMD2+ compatible. That would probably mean that the same will apply for AMD3 compatibility on AMD2/2+ motherboard.

[Webby]

All the big names including ASUS, Gigabyte, DFI, MSI have all released BIOS updates or announced the intention to do so for the AM2+ boards for AM3 CPUs.

As long as you get one of the compatible chipsets which is anything in the 7 series (so basically if its AM2+ chipset and made by AMD it will get an update I assume nvidia will do the same) you will be fine for AM3 CPUs.

As to how long AM3 CPUs will support AM2+ motherboards that will be down to a couple of factors first how long the motherboard manufacturers update the BIOS's for and secondly how long AMD incorporate a DDR2 controller onto the AM3 CPUs. Both of those questions are unanswerable as we can not see into the future and don't work for AMD.

[Sputnik]

From my experiences by the time you decide you need to change CPU, They no longer make anything that will fit into your motherboard and your memory is the wrong type for new boards.

I'm looking at upgrading to another AMD based machine soon. Which will be the 5th AMD set up in a row for me.

[Kumagoro]

Thanks for the replies,

I personally don't think upgrades are economical and I always just start a fresh as well. But this
is for a friend and I may not be around to build him one again in a few years so an upgrade when he
needs it will be better for him.

Like I said I will be going for an E5200 or 7750 as he doesnt need a quad now. When he does
he can just get one on the cheap. My thought was that if a 32 nm AM3 will work with the current
AM2+ then that will likely be better than the current intel quads. Seeing as there is no info from
AMD at all about the possibility, there seems little worth in opting for the lesser 7750 now.
I was just hoping someone had heard that was what they were planning.

[Sputnik]

I was going to go with the 7750+ but, now thinking of a Phenom 2.

[CAT-THE-FIFTH]

Unless you are overclocking a 7750+ BE is actually faster than an E5200 for gaming at stock speeds:

http://www.bit-tech.net/hardware/cpu...-cpus-review/5

http://www.guru3d.com/article/amd-at...0-be-review/11

Also the AMD motherboards tend to be cheaper and better specified than the equivalent Intel motherboards.

Edit: I meant the cheaper motherboards.

[Kumagoro]

~I will def be overclocking it as far as I can.

In what way are the boards better specified.

[CAT-THE-FIFTH]

If I was not around to support a PC I would not be building an overclocked pc for him. If he knows how to do it then fair enough.

For AV use most of the sub £60 motherboards for socket 775 are not as good as the equivalent AMD motherboards IMHO although YMMV.

Also there used to be some good budget overclocking motherboards for a socket 775 until a month or so ago for under £60. There was even a Gigabyte with all solid capacitors for under £50. How much will it cost to get a motherboard capable of some decent overclocking and a PCI-E slot not affected by FSB frequency??

It maybe better to just get cheaper motherboard and invest the money saved in a faster processor like an E7200. If he does upgrade to a socket 775 quad later on then he will also get more money for a faster processor.