Front Side Bus

[webtek]

I have purchased a syntax mobo, from newegg. One of the board specs said that it had 266/333 fsb. When I got the board and looked at the specs in the manual it states that it has 133/166 fsb. I’m confused????? Does this have to do with the memory at all or also. I have DDR 2700 (256mb) going on this board as well. Also a new Barton 2500 AMD processor that runs at 333mhz.

With the risk of sounding like a moron, could someone explain the FSB specs and what they mean and / or pertain to.

Thanks in advance
RIch

[Terminator]

FSB is the external frequency but the Athlon series of processors use dual pumping which gives 2x the FSB. The DDR memory also uses double data rate , again 2x the FSB.
In comparison the newer pentium processors use quad pumping 4x FSB.

You can set on most motherboards the memory to run at different speeds to the CPU but again what you set it at you double to get the effective speed. I don't recommend running in this asynchrynous mode.

So what you set your FSB to you have to double it to get the frequency that your CPU and RAM run at. 133 ->266 . 166 ->333

Set it to 166 for your Barton 2500 (333MHz) and this will run in sync with your PC2700 ram. (333MHz)

I'm assuming this is the PC Chips Syntax Via KT266 motherboard?? I didn't think this board ran above 266(133x2)MHz but maybe it's a newer version/BIOS update. I thought they maxxed out at 266MHz.

T

:t

[Strawbs]

The confusing part is brought about by the DDR spec. DDR stands for Double Data Rate, meaning that data transfer will take place on the rise and fall of the clock cycle, effectively double the 133\166 fsb figures the manual states! PC2700 is also DDR RAM and runs at the same speed by default! all that you have will be perfectly matched (speed wise) when you install it!

You may have to set the FSB manually (study the Manual for pointers to setting up your board's speed) the first time you boot up, and the BIOS may display a Front Side Bus speed as low as 100MHz, this is usually to avoid burning out lower speed CPU's. Enter the BIOS and set it to 166MHz, if you go over that speed you will be entering the realms of overclocking and run the risk of permanent damage to your new hardware!

Make sure you apply thermal paste or a pad to the base of the heatsink and that you have the "cutaway" on the hsf turned toward the "step" on the socket when you assemble it, - or you may cause the CPU to overheat and die instantly!

Take a look at >this sticky (http://www.sysopt.com/forum/showthread.php?s=&threadid=145455) for a few tips!

:t

[webtek]

THESE ARE MY BOARDS SPECS

SYNTAX VIA KT266A Chipset Motherboard for AMD Socket A CPU, Model "SV266AD" -RETAIL


- Specifications -

Supported CPU: Socket A for AMD Athlon XP/Athlon/Duron Processor
Chipset: VIA KT266A + VT8235
FSB: 266/200MHz
RAM: 2x 184-pin DIMM support DDR266/200 Max 2GB
IDE: 2x UDMA 133 up to 4 Devices
Slots: 1x AGP 4X, 5x PCI
Ports: 2xPS/2,1xCOM,1xLPT,1xLAN,6xUSB2.0(Rear 4),Audio Ports
Onboard Audio: VIA VT1612A AC'97 CODEC
Onboard LAN: VIA VT6103 10/100 Mbps Ethernet
Form Factor: ATX

Model#: SV266AD

[dajogejr]

Personally...
I'd RMA that board for something a little more "future proof"

Your newer AMD CPUs are 333 and 400MHz FSB.

It would be nice to at least accomodate your CPU and RAM with 333 FSB...

You can find plenty of Via or NForce chipset boards on newegg for very, very cheap.

50 bucks on up...

[webtek]

OOOOPPSSS I SCREWED UP i GAVE THE WRONG BOARD

SYNTAX SiS746FX Chipset Motherboard for AMD Socket A CPU, Model "S746FX" -RETAIL


- Specifications -

Supported CPU: Socket A for AMD Athlon XP/Athlon Processor
Chipset: SiS746FX + SiS963
FSB: 333/266MHz
RAM: 3x 184-pin DIMM support DDR400 MAX 1GB or DDR333/266 MAX 3GB
IDE: 2x UDMA 133 up to 4 Devices
Slots: 1x AGP 8X, 5x PCI, 1x CNR
Ports: 2xPS/2,1xCOM,1xLPT,1xLAN,6xUSB2.0(Rear 4),Audio Ports
Onboard Audio: C-Media CMI9738 4-Channel CODEC
Onboard LAN: RealTek RTL8201BL 10/100 Mbps PHY
Form Factor: ATX

Model#: S746FX

[dajogejr]

Oh...scratch my gig...then.

Just set the FSB to 166, which...is 333
Set the multiplier to 11
Set the RAM to run either at 100% or by spd. it's the same thing...really.

And, wholoaaa....
All set.

Y(our) chip was designed to run at 1.833 MHz...

Which, is effectively....
11 X 166
Rounds out to just a hair under 1.83...:)

[Eric Legge]

See these tables for an illustrated explanation:

http://www.legge40.freeserve.co.uk/RAM.htm#ddr

Includes DDR2 in the second table.

The PC Name is the bandwidth, or eight times the figure in the DDR Name, because data is transferred in blocks of 8 bytes. 1MHz transferring 1 byte per second is 1MB/s. DDR400 is PC3200. 400X8 = 3200MB/s.

Eric,
http://www.legge40.freeserve.co.uk/BuyerBeware.htm