Were slot mounted CPUs a good idea?

I was just thinking how sweet it would be if the CPU was mounted like graphics cards. Installation would be so much easier. I know old CPUs used to do this.
Is it possible to produce a modern CPU with a pin count low enough to fit in a slot similar in size to a PCI-e slot?

Just curious...
27 answers Last reply
More about were slot mounted cpus good idea
  1. I suppose you could if you made the pins wider(bigger) to make up for the lack of? 5 big ones instead of 10 small ones for a quick example.
  2. That doesn't make much sense. I mean, most of the 775pins on a modern intel CPU have a purpose right? Im wondering if there is a way to design a cpu with less pins and maybe a large common ground pin so you can actually fit it in a slot of 250 ish pins.

    old p3



    Believe it or not this is a photoshop.

  3. I think one problem was cooling the cpu and the amount of space a cpu and heat sink would take up in a system if mounted that way. Think about how big some of those cpu coolers are.......
  4. Customisbetter: Id say latency would get a huge problem with that.
    also hypertransport's or intel's quickpath's speed will be negated with a slot based thingie..

    also, slots dont let you have that nice cooling solutions, everything will have to be sided
  5. Pin count isn't the issue, cooling it is.
  6. The reason for the slot CPU was room for the cache memory chips.
    On the socket boards of that time, the board had to have sockets on the motherboard for L2 cache.
    My old IBM computer had 2 sockets for L2 that at the time cost an extra $70.
    In a system that had a 133Mhz Pentium.
    As CPU size got smaller the L2 was put on die.
  7. The reason Intel went to the slot design was to further distance itself from AMD. At the time both platforms were using Socket 7 and chipsets were semi-interoperable. At this time Via and SiS were much stronger competition in the chipset business. Intel gave the excuse that there was bandwidth limitations using a socket design (total BS) and said that the future was in slotted designs. Of course AMD followed suit shortly after, not because they agreed, but because the public bought the lie and viewed socketed CPU's as a dead end. So AMD followed because of marketing pressure and public perception.

    A few years later, Intel moved back to the socket design with Socket 370 and hasn't looked back. Of course the slot design made it easier to add L2 cache (as others have mentioned), but it wasn't Intel's primary reason for pioneering the technology.

    One thing in favor of a slotted design, is there are no pins to bend (either on the CPU package or socket).

    The main reason we won't see a slotted design return is latency as someone mentioned. With such high bandwidth requirements adding trace lengths to interface the CPU with the northbridge would add too much latency, and motherboard design complexity (to combat the latency). Also cooling would be more difficult as has been mentioned before. As for pin counts, most of the pins on modern CPU's are used for Vcc and ground. This is necessary due to the amount of current needed by contemporary CPU's.
  8. Lame.
    Well, i guess i will just have to continue screwing my intel CPU cooler into place after every upgrade. Unless CUDA really takes off...

    Thanks for the info!
  9. can anyone here imagine a future of much smaller electronics? a future of operating systems and all programs running from CUDA, a future with a number of graphics cards on a motherboard, with no cpu, system ram, northbridge or southbridge? just plug the sata10 cable into the GPU with 32GB of RAM and let it fly? could this be the way of the future o.O
  10. I dont see that happening any time soon. By that I mean I dont see it happening within the next 10 years. Personally I think things are going backwards in size. Look at the size of video cards, they are getting longer and longer. ****, its gotten so bad that 90% of the cases out there cant even support anything longer than a 8800GT.

    Then you have cooling solutions, getting larger and larger. Giant copper blocks and pipes spanning a quarter of the motherboard, CPU coolers that are 6 inches tall and weigh 2 pounds.

    Die shrinks, yea. But the chip itself is staying the same size. Hell, i7 is actually bigger physically than current chips.
  11. V3NOM said:
    can anyone here imagine a future of much smaller electronics? a future of operating systems and all programs running from CUDA, a future with a number of graphics cards on a motherboard, with no cpu, system ram, northbridge or southbridge? just plug the sata10 cable into the GPU with 32GB of RAM and let it fly? could this be the way of the future o.O


    In a few years, we could slot in a board with another 16 cores (8 GFX, 1 SFX, 4 Physics and 3 CPU) to increase your gaming. Or an 8 core card with specialised server-based core logic, "30387's" and helper, media decoders, anything, or a card for a general range of apps (Video, CAD etc). Any combination would be possible.
  12. techgeek's comments were excellent.
  13. *Thinks* maybe one day GPUs will have sockets on motherboards to help with cooling demands
  14. Here lads read this it explains the reason for the move to the slot cpu design.
    http://preview.tinyurl.com/58tp7j

    The slot design was a logical next step as cpu's increased in speed, until the cpu die size was reduced to where it allowed for the cache to be on die.
    Everything else was just marketing hype.

    Small excerpt;

    PC Systems, Installation and Maintenance: Installation and Maintenance - Google Books Result
    by R. P. Beales - 2004 - Computers - 472 pages
    ... reason why Intel and AMD moved from socket CPUs to the radically different slot design, was to incorporate the Level 2 cache chips as close to the CPU ...

    I do hope this answers your question customisbetter.
  15. *Thinks* GPU's will be partnered with CPU's on at least an MCM but eventually a combined CPU/GPU solution for the low end of the market soon enough.

    I couldn't see a Phenom and a NV280 chip wedged any closer than a couple of inches or "critical mass" might be reached and the poor gamer end up ash on the floor.

    Power supply manufacturers are already scratching their heads as it is.

    The bandwidth possibly achieved with that kind of solution is awesome ... at least in terms of numerical power ... look at Tesla now ... and that is across a PCIE bus ... imagine them connected via HT3 or Nehalem's new bus (which I forgot ... sorry).
  16. Even with technology now there would be no way to lower the pin count. Right now as it stands with the IMC and tri channel DDR3 Intel uses the 1366, 1156 with dual channel DDR3. AMDs socket G34 is going to increase the pin count as well.

    Thats where a lot of the pins come from, the IMC and channels of memory. So id Intel went with quad channel DDR3 I am sure the pin count would go up with it as well.
  17. @Thread title: *Looks at current CPU lineups* Apparently not...
  18. B-Unit ... with his usual aplomb stuns us all ... heh heh.

    Very good point.
  19. Top points to Custom for the cool card.

    I remember having a P3-550 with an aftermarket chrome cooler ... it was pretty ...

    Don't know how much better it was ... bit like them Orb coolers ... all show and no go.

    Sorry for the double post but I can't edit ... that functionality on the good ship THG seems to have died ... hopefully we won't lose life support ... heh heh.
  20. customisbetter said:
    I was just thinking how sweet it would be if the CPU was mounted like graphics cards. Installation would be so much easier. I know old CPUs used to do this.
    Is it possible to produce a modern CPU with a pin count low enough to fit in a slot similar in size to a PCI-e slot?

    Just curious...


    Gosh, I didn't think installing a CPU was THAT hard. Drop it in, push a lever?
    The old cards were necessary step, at the time the only way to get the cache memory off the motherboard and tied to the CPU running at the same speed as the CPU. But, the cards are bulky, and give you longer paths back to the motherboard. Not really practical at all with the speed of todays processors, die size, and memory cache sizes. Why stick it all onto a card when it fits so nicely right into 1 tiny square directly on the motherboard?
  21. The slot would have to be twice the length or some kind of multiplexed setup now ...
  22. ^^^I was really referring to the installation of the HSF.
    with intel, you have to screw it in and listen to that horrible sound of the springs scraping against the bracket. Or take a risk with pushpins.

    On the AMD side, its a bit easier, but i have heard of people bending pins when the CPU gets stuck on the heatsink.

    I know its just a minor inconvenience.
  23. The poor heat sink mounting design that everyone seems to have, especially Intel, is not because the CPU is in a socket, or a card in a slot. It is just bad engineering, and Intel could do better. Can you imagine trying to put a heatsink with cooling pipes, a huge radiator onto a card? The card would have to stick out of the motherboard quite a long ways to get some of these on!
    Then, rather than the whole appartatus sticking straight up off of the motherboard, it is going to laying parallel to the board taking up all kinds of room directly above the card! I don't know, but I can't see any advantage to having CPUs mounted on cards.

    Andno matter how idiot proof you make it, there will always be some fat fingered buffoon, like me, who will manage to break or screw it up somehow if you are not careful and pay attention to what you are doing.
    Someone would surely try to plug the card into the wrong slot, I guarentee it.
  24. +1 for the idea that the Intel engineer who came up with the 'push-pin' mount should be taken outside and shot. You know its a bad design when no OEM manufacturer uses it, they all build screw plates into their cases.
  25. You could get a slot CPU not to far back. Some one (Asrock?) made a board that had a S939 I think, and produced "daughter cards" for AM2, and 775. Each daughter card had the socket, and ram slots. I think Via made the northbridge which I *think* stayed on the main motherboard. This was around perhaps 2 years ago?

    As already stated, the slot design was to get the L2 cache closer to the chip. Now that our manufacturering process is so small, its not really needed. Thats not to say a slot design couldn't work, as I just mentioned a "recent" example.
  26. 4745454b said:


    As already stated, the slot design was to get the L2 cache closer to the chip. Now that our manufacturering process is so small, its not really needed. Thats not to say a slot design couldn't work, as I just mentioned a "recent" example.


    The slot design was to cheaply/b] get off-die L2 cache closer to the chip. The Pentium Pro was the first Intel x86 processor to have L2 cache that wasn't mounted on the motherboard and it used a socket (the funky-looking oblong Socket 8 with two pin pitches.) The Pentium Pro had the cache chips in the CPU package with the die via an MCM and hooked the L2 cache and the core over a backside bus. The problem with that approach is that it was much more expensive than putting third-party SRAM chips on a daughter card, so Intel went the cheaper daughter card route until they had a process node suitable to put a sufficient quantity of L2 cache on-die- and voila- Socket 370 was born.

    AMD was a little bit of a different case as they made socketed processors with onboard L2 cache about the same time they did slotted CPUs. The K6-2+ and the K6-III/K6-III+ had onboard L2 cache and were socket 7 while AMD also rolled out Slot A Athlons with off-die L2. Supposedly AMD went the slotted route because Slot A was their first interface not compatible with Intel CPUs and Slot A is simply Slot 1 turned 180 degrees with different pinouts, letting motherboard manufacturers easily make Slot A boards without needing any AMD-specific parts.
  27. 4745454b said:
    You could get a slot CPU not to far back. Some one (Asrock?) made a board that had a S939 I think, and produced "daughter cards" for AM2, and 775. Each daughter card had the socket, and ram slots. I think Via made the northbridge which I *think* stayed on the main motherboard. This was around perhaps 2 years ago?

    As already stated, the slot design was to get the L2 cache closer to the chip. Now that our manufacturering process is so small, its not really needed. Thats not to say a slot design couldn't work, as I just mentioned a "recent" example.



    Ahhh yes I have two of those boards with one of them having the expansion upgrade board for an AM2 CPU. It works great!
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