32bit or 64bit

[Kuzi]

I noticed on Anandtech they used 32bit Vista for the Phenom review, and on Cinbench 10:

Q6600 got 8647
Phenom 9850 got 7986

But at techreport they used 64bit Vista for testing, and 64bit Cinbench, the results:

Phenom 10071
Q6600 9837

Why would Phenom be 8% slower than Q6600 on 32bit Cinbench, but a little (2%)faster on the 64bit version?

 

[nyker96]

maybe it's got a better 64-bit engine. I think 2% hardly statically anything.

 

[crimson117]

Different test beds, too, so you couldn't compare even if they both used the same OS.

 

[Zstream]

Originally posted by: crimson117
Different test beds, too, so you couldn't compare even if they both used the same OS.

It would be nice to see some 64bit reviews. Not saying I would jump on the bandwagon but if it helps with multi-core then I just might.

 

[Kuzi]

Originally posted by: nyker96
maybe it's got a better 64-bit engine. I think 2% hardly statically anything.

2% faster than Q6600 when using 64bit version, but 8% slower than Q6600 on the 32bit version, 10% difference, that is not small.

Both processors have higher performance on the 64bit version, but the Phenom gained much more. I'm not sure, maybe you are right about a better 64bit engine in Phenom.

 

[Glavinsolo]

Go 64bit. I recently decided to do so, and its an amazing difference. I enjoy the fact that vista puts your program files in different folders for those who are 32bit vs. 64bit. everything runs smooth.

There are no deep negatives of going to 64bit but there are plenty of positives if you have the option.

 

[bfdd]

Originally posted by: Glavinsolo
Go 64bit. I recently decided to do so, and its an amazing difference. I enjoy the fact that vista puts your program files in different folders for those who are 32bit vs. 64bit. everything runs smooth.

There are no deep negatives of going to 64bit but there are plenty of positives if you have the option.

Yea I've been 64bit since Vista came out, I figured it was time for the change. The only problem is really drivers. Once they come out it's nicer. Feels a bit faster too just doing day to day things than when I was running 32bit XP before Vista came out.

 

[Ratman6161]

Originally posted by: Kuzi
I noticed on Anandtech they used 32bit Vista for the Phenom review, and on Cinbench 10:

Q6600 got 8647
Phenom 9850 got 7986

But at techreport they used 64bit Vista for testing, and 64bit Cinbench, the results:

Phenom 10071
Q6600 9837

Why would Phenom be 8% slower than Q6600 on 32bit Cinbench, but a little (2%)faster on the 64bit version?

Look at the system configurations they are using in the respective tests. Annandtech is using 2 GB of ram (2 x 1GB) while the techreport is using 4 GB (4 x 1GB). On a 4 GB system, it makes no sense to go 32 bit as you are only going to see 3.25 to 3.75 GB usable ram depending on the system.

Not entirely sure how the quantity of ram affects the test either. I don't know anything about cinebench, but perhaps it benefits from more RAM and if AMD has a faster memory controller that might be the answer? Speculation.

 

[Kuzi]

Originally posted by: Ratman6161
I don't know anything about cinebench, but perhaps it benefits from more RAM and if AMD has a faster memory controller that might be the answer? Speculation.

Even if we assume AMD benefits more from the 4GB RAM, there is no way the jump would be this huge.

It must be something with the 64Bit extentions in both CPUs, but can't make a conclusion from just one benchmark. I'll check more into this.

 

[Brunnis]

Originally posted by: Kuzi
It must be something with the 64Bit extentions in both CPUs, but can't make a conclusion from just one benchmark. I'll check more into this.

It's probably not something to do with the actual 64-bit extensions. Off the top of my head, I'd put my money on two things:

- Running 64-bit code puts a much larger stress on the memory subsystem. AMD systems have often had faster main memory access than Intel systems.

- If I remember correctly, Intel's Core 2 CPUs lose the ability to reorder load instructions before store instructions when the CPU runs in 64-bit mode. This could possibly explain some of the difference.

 

[Kuzi]

Originally posted by: Brunnis
It's probably not something to do with the actual 64-bit extensions. Off the top of my head, I'd put my money on two things:

- Running 64-bit code puts a much larger stress on the memory subsystem. AMD systems have often had faster main memory access than Intel systems.

- If I remember correctly, Intel's Core 2 CPUs lose the ability to reorder load instructions before store instructions when the CPU runs in 64-bit mode. This could possibly explain some of the difference.

That's interesting. People will eventually move to 64bit I guess, but by that time, say a year or two from now, Intel will have Nehalem which means any benefit AMD may have in such a case may be gone.

I personally will get 64bit Vista when I build a new system this year.