AMD Athlon 64 X2 Compatibility with IA-32

Killswitch

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Hello,

I am looking to build a new system with a AMD Athlon 64 X2 3800+ CPU and have a few questions before taking a lot of damage on the pocket. I am primarily a software guy so please excuse any technical naivety that is reflected from my questions.

The AMD Athlon 64 and the Athlon 64 X2 series supports the AMD64 architecture. And the AMD64 architecture natively also supports the IA32 architecture, as it was an extension of the 32 bit x86.

I was wondering if there are any known incompatibilites when running software written in 32 bit on an Athlon 64 or 64 X2 ?

Do I have to run the 64 bit versions of Linux (or windows) distribution on these CPUs, or can I still run the 32 bit versions ?

If there is a restriction that I must use a 64 bit OS, does this extend to software that I run that in that OS as well ? As in, any software that currently runs on my 32 bit Intel machine, will they also run on these AMD CPUs ?

Thanks a lot.
 

pat

Expert
Hello,

I am looking to build a new system with a AMD Athlon 64 X2 3800+ CPU and have a few questions before taking a lot of damage on the pocket. I am primarily a software guy so please excuse any technical naivety that is reflected from my questions.

The AMD Athlon 64 and the Athlon 64 X2 series supports the AMD64 architecture. And the AMD64 architecture natively also supports the IA32 architecture, as it was an extension of the 32 bit x86.

I was wondering if there are any known incompatibilites when running software written in 32 bit on an Athlon 64 or 64 X2 ?

Do I have to run the 64 bit versions of Linux (or windows) distribution on these CPUs, or can I still run the 32 bit versions ?

If there is a restriction that I must use a 64 bit OS, does this extend to software that I run that in that OS as well ? As in, any software that currently runs on my 32 bit Intel machine, will they also run on these AMD CPUs ?

Thanks a lot.

No, AMD64 CPU will run 32 bit just fine and fast. Intel EM-64T instruction are the same that are prensent on AMD 64 CPU. some time ago, on first Intel 64 bits CPU, 2 instructions were missing from the set, but have been added for full compatibility with AMD, which is the standard for 64bits extensions on 32 bits CPU.

You won't have any compatibility whenever you run an AMD or Intel CPU with 64 bits instructions with current 32 bits apps and OSes.

You won't have any problem with the X2 3800+ and current software. Take note that, not all application are written to fully take advantage of dual core CPU. But, the dual core will multitask better.

And this CPU runs XP 64 bits or Vista, when available. And it runs Linux 64bits distro very well too.
 

Killswitch

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Great, thanks a lot for your reply.
I am assuming that running a 64 bit version of the OS, as opposed to the 32 bit version, will be better as they will actually use some of the advantages offered by 64 bit ?
 

pat

Expert
Great, thanks a lot for your reply.
I am assuming that running a 64 bit version of the OS, as opposed to the 32 bit version, will be better as they will actually use some of the advantages offered by 64 bit ?

It could. But problem is, not all manufacturer has 64 bits drivers for the OS. So, while you may have a nice OS, it will be pretty useless if your printer, IE, don't have any drives..

Vista will be the next big thing in the OS. I would stick with 32 bits for now, and wait for Vista.
 

Killswitch

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Great, thanks a lot for your reply.
I am assuming that running a 64 bit version of the OS, as opposed to the 32 bit version, will be better as they will actually use some of the advantages offered by 64 bit ?

It could. But problem is, not all manufacturer has 64 bits drivers for the OS. So, while you may have a nice OS, it will be pretty useless if your printer, IE, don't have any drives..

Vista will be the next big thing in the OS. I would stick with 32 bits for now, and wait for Vista.

Ok, thanks for letting me know.

So I understand that a 32 bit driver will not work with the 64 bit OS. Is this the same as other Software though ? For example, Games, Browsers etc. that run in my 32 bit machine; will all these Software will also be incompatible with a 64 bit OS ?
 

ltcommander_data

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Generally most 32-bit programs will run fine on a 64-bit OS. Both the OS and the processor are specifically designed with a compatibility mode to run 32-bit programs. You might want to make sure you are running the latest versions to avoid any problems but it should be okay. They won't receive full benefit of a 64-bit environment though. Performance is similar, some slightly slower, some slightly faster.

If you are a Windows user, you should really wait until Vista to move to a 64-bit OS. Unless you need lots of RAM, ie greater than 4GB, there is little benefit to move over now. Your AMD X2 will run just as well on a common 32-bit OS. That way you'll avoid these compatibility issues.
 

Killswitch

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Great, thanks a lot for that info. On my new system I do plan to run Windows. From your suggestions, I will just install a 32 bit version of Windows XP, and wait until Vista to change over.

Well this is my first time moving over to a non Intel CPU. Hopefully I won't regret it :)
 

pat

Expert
That's what I do, waiting for Vista. I do lot of video editing and I know that I could benefit from putting a X2 on my board, but I rather wait to see new chipset and motherboard for socket M2 CPU. My A64 has yet to run any 64 bits apps, but it perform so well in 32 bits apps and run so cool compared to Intel offering that I won't switch for a while.

Intel and AMD are not different in quality and compatibility. The only difference come in motherboard. If you get quality parts for you AMD CPU, you'll likely have problem. If you get cheap generic parts for your AMD or even Intel, then you're going to run into problem with both.

Most problem come from memory compatibility. This kind of problem is not only for AMD motherboard, but for Intel too.
 

Rob423

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So what is Currently the Best motherboard for running an X2 4800+?

i see them being paired up with the MSI neo4 platinum and the asus a8n Sli... but i don't want SLI and don't have any intentions of running 2 gfx cards. but also i won't be purchasing till around January, so i guess i'll just wait. but i was just wondering.

Rob423..
 

slvr_phoenix

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I still say avoid MSI like the plague. :O They're just too much of a crap shoot for me.

And I think Asus high-end stuff is really good. It's just their low end stuff that can be crap.
 

Killswitch

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I was gonna go with something like this for 95 bucks:

ASUS A8N-SLI Premium Socket 939 NVIDIA nForce4 SLI ATX AMD
Motherboard -
Retail
AGP Slots: None <--- Have to work on that :)
CPU Type: Athlon 64FX/Athlon 64/Sempron/Athlon 64 X2
DDR Standard: DDR 400 (PC 3200)
Dual Channel Supported ECC Supported: Yes
FSB: 1000MHz Hyper Transport (2000 MT/s)
Maximum Memory Supported: 4GB
Number of DDR Slots: 4x 184pin DDR

what do you think ?
 

pat

Expert
Well, if you want an AGP slot, then forget nforce4. ULI, nforce3 and VIAkt800 has AGP. And if you plan to stay with AGP, then forget SLI. it is only for nvidia PCI-e card. A board like the GA-K8U-939, by Gigabyte could be a nice modern board for your X2 and AGP.
 

Killswitch

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I checked out that MOBO:

# GIGABYTE GA-K8U-939 Socket 939 ULi M1689 ATX AMD Motherboard - Retail

AGP Slots: 1x AGP 8X/4X
CPU Type: Athlon 64 FX/Athlon 64/Athlon X2
DDR Standard: DDR 400 (PC 3200)
Dual Channel Supported: Yes
Maximum Memory Supported: 4GB
Number of DDR Slots: 4x 184pin DDR
PATA: 2 x ATA 133 up to 4 Devices
PCI Slots: 5
SATA: 2 x SATA 150
SATA RAID: RAID 0/1 JBOD
# Model #: GA-K8U-939

You are right, it does look pretty good for about 65 dollars.
After doing some research it looks like PCI express is the new technology with double the bandwidth of AGP.

From what I read so far PCI Express and AGP Cards are pumping out similar framerates in today's games. Maybe the next generation games will perform better with PCI Express. Unless someone actually saw real difference.

I don't know if it is a wise idea to stick to AGP. It looks like PCIexpress is the new thing and to stay futureproof, or at least try to, I will need to consider a MOBO with PCI express slots.

I was thinking of getting a MOBO that has one AGP slot but also has PCI express slots. This way even if I get an AGP Card now, the PCI express option remains open. Is this at all a possible configuration, or its either AGP or PCI express ?
 

Rob423

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yea im not going AGP deff sticking with PCI-E

probley gonna go with the BFG 7800GTX... unless by jan or feb something that totally destroy's that comes out by nVidia.
 

pat

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If you don't have any video card and gonna get one, better go PCI-e right now. Usually, card are now cheaper in PCI-e than AGP, unless you can get a good deal on a fast AGP video card.