SOCKETS & SLOTS

[Guest]

In case I missed this one, can someone explain what the digression from socket to slot and back to sockets was all about? Are we anymore technologically advanced for it or was it just a red herring?

 

[Raystonn]

All Pentium II and III systems started out on slot 1. This slot was a technique to attach a processor to a mainboard. Older CPUs had used socket 7. An advantage to the slot is that the heat produced by the chip does not spread on the mainboard, but on the card itself, which can be cooled in a simpler way. Even more important is that the cache chips of a slot 1 processor were attached close to the processor, on the slot 1 cartridge itself. Due to this cache placement, the right cache chips could be selected and placed on the card.

Since 1997, some things have changed. Since the introduction of the Celeron, without any cache chips, Intel started experimenting with the placing of cache. An improved version of the Celeron, the Mendocino core, had 128KB of integrated cache. This was not very much compared to the 512KB of the Pentium II. But since the cache of the Celeron was integrated in the chip itself, it could perform at full processor speed while the 512KB of the Pentium II performed only at half speed.

This technique of integrated cache worked very well, as the Celeron performed almost as well as a Pentium II, in fact better than a Pentium II in most games. The slot 1 concept was designed to bring the cache chips closer to the processor, via the cartridge. As time passed, the system of integrated cache was found to work so well, the cache chips became integrated into the processor core. There was no longer a need for a cartridge around the CPU.

A socket design is much cheaper to implement for motherboard manufacturers as well as the CPU manufacturers. Besides heat issues, the main reason we were moved to slot based systems in the first place was to place the L2 cache in very close proximity to the CPU. Because this slot is no longer required due to the L2 cache being integrated into the CPU, we fall back to what's cheaper to manufacturers. I'm sure everyone loves it when prices drop...

-Raystonn


-- The center of your digital world --

 

[Crashman]

Not only that, but htey also provide a better connection and a shorter data path, which leads to increased performance and reduced RFI (and wan't RFI the reason for the MTH problem?).

Suicide is painless...........

 

[Guest]

Raystonn:

Thanks for your reply. You clarify a lot of the reasoning for the move to the Slot. At the time it was being introduced though, there was a lot of hype about the Slot format being the best thing since slice bread and how it was going to revolutionise the job of the maintenance engineer, facilitating upgrades etc. Your explanation therefore points to the Slot format as only a means to overcome CPU/memory overheating problems.

Of course, progress of technology must have its digressions. I just wish there was more clarity about the direction the big companies take than pure hype.

 

[Guest]

People will give you tec explanations, but the actual truth is for 3 reasons only: Marketing, Marketing, Marketing.

Intel was very annoyed that AMD and Cyrix were using their nice Socket7 archatecture for their K6's and M2's. So, when they brought out the P2, they decided to move to a slot format which had a patented bus design. Intel had the lion's share of the market at the time, so locking competitors out of motherboards designed for their chips would seriously damage the other companies prospects.

This was indeed the case until the debut of the Athlon. By then, AMD had a big enough market share to design their own bus, provided they used the same physical part being made by various fabs to glue onto motherboards. Hence Slot 1 and Slot A having the same number of pins and being the same size, but being incompatible.

Intel realised this and decided to move back to the superior socket format, simply because the inferior slot format was providing them with no advantage, and another change would get right up AMD's nose.

There may be technical points about L2 cache as well, which are important, but don't be fooled into thinking this was Intel's main reason for the choice.

~ I know the human being and fish can coexist peacefully ~