questions about AMD 64 3200+, FSB and hyperthreading

[Nikko]

I have an AMD 64 3200+ running in an Asus K8V mobo. I ran a PCMark04
benchmark on it and got a score of 4168. Running the same benchmark on my
work computer, a Pentium 3.0 Ghz I got a score of 4353. I'm not too
concerned with scores, but I noticed something in the details that caught my
eye.

In the report for the P4, PCMark says:

CPU Intel Pentium 4 2992 MHz

Physical CPUs 1

HyperThreading Available - 2 Logical Processors

FSB 800 MHz



For the AMD 64 3200+ it says:

CPU AMD Athlon(tm) 64 2203 MHz

Physical CPUs 1

HyperThreading Not Available

FSB 200 MHz


Now shouldn't the AMD chip be running at 800 MHZ on the FSB as well? And I
know AMD doesn't have hyperthreading, but they have hypertransport. Isn't
that the same thing? Doesn't PCMark recognize that? I'm just wondering if
there is something I need to turn or enable to get this right, or if it *is*
right but looks weird in PCMark. Any help would be welcome. Thanks.

 

[JK]

You didn't mention what other hardware you have in the systems. I found this.
http://forums.anandtech.com/messageview.cfm?catid=28&threadid=1346645&STARTPAGE=1

 

[General Schvantzkoph]

I have an AMD 64 3200+ running in an Asus K8V mobo. I ran a PCMark04
benchmark on it and got a score of 4168. Running the same benchmark on my
work computer, a Pentium 3.0 Ghz I got a score of 4353. I'm not too
concerned with scores, but I noticed something in the details that caught my
eye.

In the report for the P4, PCMark says:

CPU Intel Pentium 4 2992 MHz

Physical CPUs 1

HyperThreading Available - 2 Logical Processors

FSB 800 MHz



For the AMD 64 3200+ it says:

CPU AMD Athlon(tm) 64 2203 MHz

Physical CPUs 1

HyperThreading Not Available

FSB 200 MHz


Now shouldn't the AMD chip be running at 800 MHZ on the FSB as well? And I
know AMD doesn't have hyperthreading, but they have hypertransport. Isn't
that the same thing? Doesn't PCMark recognize that? I'm just wondering if
there is something I need to turn or enable to get this right, or if it *is*
right but looks weird in PCMark. Any help would be welcome. Thanks.

Hyperthreading: Running multiple instructions streams simultaneously.

Hypertransport: A highspeed interconnect used to connect the AMD64s to
their IO systems and to each other.

As you can see these are two completely unrelated things.

The Athlon 64, 754 has a single DDR channel which can run up to 400MHz
depending on the RAMs that you have connected. The data rate on a 400MHz
channel is 800Mwords/second or 3200Mbytes/second. Your RAM may be slower
than 400Mhz but I doubt that its running at 200Mhz. The slowest it's
likely to be is 266MHz, and it's probably 333MHz. Take a look in the BIOS
to see what the memory speed is set at, I expect that PC Mark is just
plain wrong.

The P4 has an 800MHz frontside bus which connects to bridge chip which in
turn connects to two banks of 400MHz DDR RAM. So the P4 has twice the
memory bandwidth of a 754 pin Athlon 64 (the Opterons and the 939 pin
Athlon 64s have two DDR channels so they have the same memory bandwidth as
the P4). The Athlon 64 has significantly lower memory latency that the
P4 which helps it a lot. It also has a big cache, 1M, so the lack of
memory bandwidth is pretty well compensated for.

 

[Nikko]

You didn't mention what other hardware you have in the systems. I found

this.


Here is the other hardware I have. Also, I'm running it on WinXP Pro, with
SP1

BFG 6800GT
2 Maxtor 160 GB HDD (not in a RAID array)
1 gig PC2700 Crucial Memory

 

[JK]

Why aren't you using PC3200 ddr ram? That seems like at least
part of the reason for the low score.

 

[Chris Stolworthy]

this.


Here is the other hardware I have. Also, I'm running it on WinXP Pro, with
SP1

BFG 6800GT
2 Maxtor 160 GB HDD (not in a RAID array)
1 gig PC2700 Crucial Memory

I would recommend getting PC3200 Ram that should have a fairly significant
impact on your scores. You may also have to go into the BIOS and "tweak"
your FSB settings. I know that my board would default to a 200Mhz FSB when
the BIOS is reset. IT does this as a precaution, it clocks to the lowest
speed possible so that every processor can run on it even if they don't
support the fast FSB speeds. Typically you have to go in and manually
change this.

 

[Nikko]

I would recommend getting PC3200 Ram that should have a fairly significant
impact on your scores. You may also have to go into the BIOS and "tweak"
your FSB settings. I know that my board would default to a 200Mhz FSB when
the BIOS is reset. IT does this as a precaution, it clocks to the lowest
speed possible so that every processor can run on it even if they don't
support the fast FSB speeds. Typically you have to go in and manually
change this.

I went in to check and it looked like my FSB for the CPU goes from 200-300
only. I assume anything over 200 would be considered OCing it, right? I
guess I don't really understand how this relates to how fast my RAM FSB
runs. Are they the same setting? Do I have to change the ratio in bios?
What should the ratio be for PC2700? What if I upgraded to PC3200? Thanks
in advance for any help you can provide.

 

[Chris Stolworthy]

I went in to check and it looked like my FSB for the CPU goes from 200-300
only. I assume anything over 200 would be considered OCing it, right? I
guess I don't really understand how this relates to how fast my RAM FSB
runs. Are they the same setting? Do I have to change the ratio in bios?
What should the ratio be for PC2700? What if I upgraded to PC3200? Thanks
in advance for any help you can provide.

Well Pc2700 Ram is only set to operate at 166Mhz (166X2=332 I.e333) So it
only supports up to a 333 FSB. Pc3200 Ram however is rated for 200Mhz
(200X2=400Mhz). The FSB and memory BUS are the same, so you are actually
just increasing the bandwidth from processor to ram when you increase FSB.
You can *try* and Oc your memory but if it won't support it then you will
start getting some serious sytem instability.