Athlon 64 FSB 400 or 800 mhz ?

[rainz]

Just saw 2-3 sites which they say the Athlon 64 FSB = 800 mhz .. Really ? is it 400 mhz (2x200) or 800 mhz (4x200)

I know the HT ( Hyper Transport ) is at 800 mhz but is it something completly different or the same thing ( if the HT is at 800 = FSB same speed .. no idea ) .. Well i need someone to clear this out.

Thx !

RainZ

 

[incurable]

Just saw 2-3 sites which they say the Athlon 64 FSB = 800 mhz .. Really ? is it 400 mhz (2x200) or 800 mhz (4x200)

I know the HT ( Hyper Transport ) is at 800 mhz but is it something completly different or the same thing ( if the HT is at 800 = FSB same speed .. no idea ) .. Well i need someone to clear this out.

Well, technically, K8 / Hammer-based processors don't have a Front Side Bus at all, because their memory controller is on-die.

What FSB in the context of Opteron/Athlon FX/Athlon 64 refers to however is the HT interface, and 800 MHz is the current top speed today's AMD processor support on that. (AMD will move to 1000 MHz HT in the near future.)

cu

incurable

 

[Tim]

Just saw 2-3 sites which they say the Athlon 64 FSB = 800 mhz .. Really ? is it 400 mhz (2x200) or 800 mhz (4x200)

I know the HT ( Hyper Transport ) is at 800 mhz but is it something completly different or the same thing ( if the HT is at 800 = FSB same speed .. no idea ) .. Well i need someone to clear this out.

Thx !

RainZ

The Athlon 64 does not have a FSB (or rather it is internal and running at CPU speed). When someone claims that the A64 has a 400MHz FSB they are properly talking about the memory speed (DDR400/PC3200), when they claim the FSB is 800MHz or 1600MHz they are most likely talking about the HT-connections.

 

[rainz]

Ok sounds good but the question is..

Why in my Bios i have the following options under ( i have the Asus K8V Deluxe Motherboard ) ..

Config System Frequency / Voltage
=======================
CPU FSB Frequency = 200 Mhz ( i can set it at 200mhz upto 300mhz )

RainZ

 

[3dilettante]

Ok sounds good but the question is..

Why in my Bios i have the following options under ( i have the Asus K8V Deluxe Motherboard ) ..

Config System Frequency / Voltage
=======================
CPU FSB Frequency = 200 Mhz ( i can set it at 200mhz upto 300mhz )

RainZ

I'm pretty sure that the bios is actually referring to the 200 Mhz reference clock that the CPU and HT links use.

HT transfers data four times a per clock to arrive at the PR Mhz of 800.

 

[Tim]

I'm pretty sure that the bios is actually referring to the 200 Mhz reference clock that the CPU and HT links use.

Correct

HT transfers data four times a per clock to arrive at the PR Mhz of 800.

Wrong, HT runs at 800 real MHz at double data rate for a total effective 1600MHz.

 

[3dilettante]

HT transfers data four times a per clock to arrive at the PR Mhz of 800.

Wrong, HT runs at 800 real MHz at double data rate for a total effective 1600MHz.

Whoops, I mixed up the clock multiplier the HT links used with the data rate.