FBS Matching

[BombaTwist]

Do i have to match a CPU FBS with a MotherBoard FBS?

Example: I have a 266MHz FBS Processor, but the Motherboard has FSB 400/333MHz.

does the motherboard have to have the same FBS as the CPU?

[boooggy]

if u have a cpu with 266 fsb the mobo will function at the same fsb. better check with your mobo's manual.

[BombaTwist]

so whats the point of a motherboard detail saying (for example:FSB 400/333MHz) then?

[jcarle]

Be very careful! You may get suprised by the fact that newer motherboards do NOT support slower FSBs in most cases.

I had the problem recently when trying to rebuild a machine with a shorted power supply. The processor, an Athlon Thunderbird 1300+ had a FSB of 200MHz and didn't have support on most motherboards I found. Finally ended up installing it on an ASUS A7S8X-MX which had support for 200/266/333 FSBs. Most current motherboards support only 266/333 or 266/333/400.

See if the CPU is slower then the maximum FSB of the board, then the board will simply slow down to the FSB of the CPU. However, if the FSB of the CPU is not within the supported range, most of the time the board won't even boot.

[boooggy]

the point is to buy a new cpu with faster fsb.....

[Bluelight]

It's not FBS, and not fsb, it's FSB (Front Side Bus)..

He he, I know I'm a stupid a** trying to correct people... Tsk tsk..

Most Motherboards do support low external clock settings even on new MoBo's if the CPU has same socket and supports the Technology..

If the CPU is a Athlon XP and the Motherboard supports for instance Athlon, Duron, Athlon XP.. Then it should support the speed of the CPU..

But you will easily find that out if you enter BIOS and try to set the FSB at the value needed..

If the CPU supports 266MHz FSB, then you will have to set the external clock speed in BIOS to 133..

Even my newest MoBo supports 400/333/266, but it don't support eny CPU with that low FSB..

You chould ofcause run a 400 FSB CPU at 266, but whats the point in doing that?

The AMD Sempron 2600+ / 1.83 GHz runs at 333MHz was the lowest I found, and it's not supported by this MoBo..

There might also exsist MoBo producers making MoBo's that don't support very slow FSB, but when it say 400/333MHz on the package, then thats usualy for comersial reasons.. Like this MoBo supports as fast as 400 FSB..

It may also support slower FSB's..

- Abit AN8 Ultra!

CPU

Supports AMD Socket 939 Athlon 64/64FX & Athlon 64 X2 dual-core Processors with 2GHz system bus using Hyper Transport™ technology

Supports AMD CPU Cool 'n' Quiet Technology

Chipset

NVIDIA NF4 Ultra single chip

Integrated NV Gigabit Ethernet and NV Firewall

Memory

Four 184-pin DIMM sockets

Support 4 DIMM Dual DDR 400/333/266 non-ECC memory

Support 4 DIMM up to 4GB Max.

Edit: But please tell me the name of the CPU and Motherboard + aditional info..

And I will soon post a reply if the MoBo supports it or not..!

Edited July 26, 2005 by Bluelight