Xbox 360 FSB?

[imported_Noob]

The Xbox 360 FSB is 21.6GB/S. What speed would that be in MHz/GHz? I heard there is a simple calculation you cna do to figure it out, if anybody knows it can you please tell?

 

[Brian23]

throughput = FSB MHz * Bus width

 

[BitByBit]

Well, we have two unknowns here: the FSB, and the Bus Width, but if we assume the bus width to be 128-bits as in the A64, then using the following formula:
Bandwidth = Frequency * Bus Width,

and rearranging...

Frequency = Bandwidth / Bus Width

we get: Frequency = 21600 / 16 bytes
= 1350MHz.

Of course, that could be way off if the Bus Width is different.

 

[IntelUser2000]

BitByBit, you are wrong with the A64's HTT Bus Width. A64 uses 800MHz/1000MHz x 2 Frequency with 16 BIT Bus Width, not 16 Byte, in two ways, so the bandwidth comes out to be 3.2GB/sec.

128-bit bus is really complex to design, I bet the bus bandwidth of Xbox is 2700MHz 32-bit.

 

[IntelUser2000]

It may even be integrated memory controller, I don't know, I think Cell in PS3 is integrated.

 

[BitByBit]

Originally posted by: IntelUser2000
BitByBit, you are wrong with the A64's HTT Bus Width. A64 uses 800MHz/1000MHz x 2 Frequency with 16 BIT Bus Width, not 16 Byte, in two ways, so the bandwidth comes out to be 3.2GB/sec.

Uh, no.
You're confusing Hypertransport with the memory interface.
Hypertransport is what connects the processor to the peripherals, such as the Hard drive, and GPU.
There is no HT link between the processor and memory.

I believe AMD still uses the double-pumped EV6 bus as the data transport medium between the two.
Dual-channel socket 939 A64s have access to 6400MB/s of bandwidth.
Doing the calculations: 6400 / 16 bytes = 400MHz - seems to support this.

128-bit bus is really complex to design, I bet the bus bandwidth of Xbox is 2700MHz 32-bit.

User Noob told us the XBox's FSB can supply 21.6GB/s of bandwidth.
2700 * 32bits (4 bytes) = 10800 MB/s, or 10.8 GB/s.

 

[miketheidiot]

ignore

 

[dguy6789]

The memory is 700Mhz from where I read, so that is 256 Bit memory.

 

[Munky]

Here's what I figure:

21.6 GB/s * 1024MB/GB * 8 bits/Byte / 700Mhz = 252.8

Seems awfully close to 256-bit, unless my math is way off.

 

[hippotautamus]

I wouldnt be surprised if it's new powerPC processor has something similar to the on-die mem controller found in a64s. I don't know much about IBM processors though..

It would HAVE to be at least 128bit to keep up with the video card its supposed to have, the throughput on a lesser one would be a huge bottleneck.

 

[Lord Banshee]

anybody else find it werid that MS is using a POWERPC and MAC for development for this xbox... i wonder if the xbox 360 runs off linux or a mac os? But i guess MS could rewrite the win2k3 kernal to use the PowerPC CPU.. but come on.. If they went though all that trouble why not make a Windows for a MAC Muahahaha lol 🙂

 

[jswjimmy]

Originally posted by: Lord Banshee
anybody else find it werid that MS is using a POWERPC and MAC for development for this xbox... i wonder if the xbox 360 runs off linux or a mac os? But i guess MS could rewrite the win2k3 kernal to use the PowerPC CPU.. but come on.. If they went though all that trouble why not make a Windows for a MAC Muahahaha lol 🙂

you know there was a windows nt that came out for power pc so its not a first for microsoft.

the cpu in the xbox is a ibm tri core 3.2ghz each one hyperthreaded

 

[IntelUser2000]

>Uh, no.
>You're confusing Hypertransport with the memory interface.
>Hypertransport is what connects the processor to the peripherals, such as the >Hard drive, and GPU.
>There is no HT link between the processor and memory.

>I believe AMD still uses the double-pumped EV6 bus as the data transport >medium between the two.
>Dual-channel socket 939 A64s have access to 6400MB/s of bandwidth.
>Doing the calculations: 6400 / 16 bytes = 400MHz - seems to support this.

Uh huh. I have never said that Hypertransport was memory interface or whatever you are misunderstanding me with. I know Hypertransport is used to connect the peripherals, I hate people like you who gets confused with what others say and make up nonsense.

I was pointing out that YOU were wrong with the Bus width on the HTT, since HTT is still a bus, its just not conventional FSB that most people think, since you said A64 had 128-bit bus.