Why is there 478 and 479 pins Pentium M??

[naro]

hi guys,

i was searching through ebay and i realised that there are 478 and 479 pin Pentium M cpu.

which one does the T40series use?

and there's desktop motherboard for Pentium M cpus, are they 478 or 479 pins??

cheers..

[smids]

There is much confusion over this but here goes.

Socket 478: Intel Desktop Socket for Northwood's, Celeron D's etc. Physical pin configuration: 478 pins


Socket 479: Mobile platform for Pentium-M Dothan and Banias. Physical pin configuration: 478 pins but one corner different pin config compared to socket 478.

Socket '480': Mobile platform for Yonah (Core Duo/Solo). Physical pin config: 478pins but different from both Dothan/Banias and Socket 478.

So basically, they all have the same number of physical pins but different configs of what the pins do (notably different pins in one corner to prevent slotting a CPU into a different socket number.

You should be looking for a Dothan/Banias which will be Socket 479 but may be termed as having 478pins - It's confusing I know but just make sure you get a Dothan/Banias of the correct FSB! If you have an i855 Chipset, you need a 400mhz FSB CPU i.e. any Banias or the '5' version of Dothans e.g. 725/735/745/755 as opposed to the 533Mhz Bus CPU's used with the Intel i915 chipset and DDR2 i.e. 730/740/750.

The T40 uses 400mhz CPU's - i.e. 725/735/745/755. All are socket 479 but only have 478pins.

There is a desktop board for these - they are made by ASUS and you need to use the ASUS CT-479 adapter on these boards to use a Pentium-M. They also need one of the later BIOS's. The P4C800 Deluxe is one of the better mobo's to use.

Check this link out: http://www.asus.com/products4.aspx?l1=3 ... odelmenu=1

Hope that gives you a little guide of what to look for .

[naro]

There is much confusion over this but here goes.

Socket 478: Intel Desktop Socket for Northwood's, Celeron D's etc. Physical pin configuration: 478 pins


Socket 479: Mobile platform for Pentium-M Dothan and Banias. Physical pin configuration: 478 pins but one corner different pin config compared to socket 478.

Socket '480': Mobile platform for Yonah (Core Duo/Solo). Physical pin config: 478pins but different from both Dothan/Banias and Socket 478.

So basically, they all have the same number of physical pins but different configs of what the pins do (notably different pins in one corner to prevent slotting a CPU into a different socket number.

You should be looking for a Dothan/Banias which will be Socket 479 but may be termed as having 478pins - It's confusing I know but just make sure you get a Dothan/Banias of the correct FSB! If you have an i855 Chipset, you need a 400mhz FSB CPU i.e. any Banias or the '5' version of Dothans e.g. 725/735/745/755 as opposed to the 533Mhz Bus CPU's used with the Intel i915 chipset and DDR2 i.e. 730/740/750.

The T40 uses 400mhz CPU's - i.e. 725/735/745/755. All are socket 479 but only have 478pins.

There is a desktop board for these - they are made by ASUS and you need to use the ASUS CT-479 adapter on these boards to use a Pentium-M. They also need one of the later BIOS's. The P4C800 Deluxe is one of the better mobo's to use.

Check this link out: http://www.asus.com/products4.aspx?l1=3 ... odelmenu=1

Hope that gives you a little guide of what to look for .

Woo... thanks for the clarification...

so the Banias and Dothans are all 478 pins, but the pins is aligned differently as compare to the Northwoods. So they call it socket 479 to differentiate it from them.

i'm actually looking at the MSI i915GM Speedster, AOpen i915Ga-HFS and the AOpen i915Gmm-HFS motherboards..

but may i know wats the difference between the PCIe-x16 and PCIe-x1 slot??? cos for the AOpen i915Ga-HFS mobo, the PCIe-x1 slot is not aligned with the PCIe-x16 slot.. will there be a difference??

[smids]

PCI-Express.

These are slots based on 'lanes'. A 1x lane has a bandwidth of 250MB/s each way i.e. to the host controller and from the host controller meaning effectively 500MB/s bandwidth.

The more 'lanes' the more bandwidth available.

A 16x slot has 4GB/s each way i.e. 8GB/s effective.

A 1 lane card can fit in any slot i.e. a 1x, 4x, 8x or 16x.

A 16x can only fit in a 16x slot - it's the same for all pci-express cards, they can only fit in a slot the same size or bigger.

Alignment physically of slots makes no difference. Note that a graphics card will always take up the 16x slot (I know of no smaller lane graphics cards at the moment - even cards which don't need 16x lanes, are made with 16). So this only leaves a x1 slot but then again, how many I/O cards do you know that actually use PCI-Express slots now? I only know of sata controllers (SiI 3132). I don't know of any sound cards etc which are PCIe.