What's stopping Intel from making ATOM into single chip cluster CPUs?

[TurtleCrusher]

Even though the atom platform itself is pretty slow in comparison to Core 2/Corei3/5/7, I don't understand why intel doesn't produce semi-monolithic Atoms into giant clusters. I'm no engineer, but couldn't intel do what they did with yorkfield and place several (4,8) Atom D510's (1.66ghz, 1MB L2, Dual Core with HT, 4 threads, 13w) on one chip? By simple arithmetic, having 16 cores/32 threads would only need a maximum of 104 watts. That's easy I imagine.

Wouldn't a CPU like this be just about the perfect multitasking CPU? It would be cheap to make (judging by their die sizes, Intel is probably making bank on these) and would be able to handle an incredible amount of tasks at a time. Not to mention multithreaded tasks (video encoding, Excel, flash) would be not out of the question.

What's stopping intel from doing this? Would it destroy their server market by offering a CPU with that many threads?

 

[theevilsharpie]

Sun produced exactly this type of processor with the UltraSPARC T1 and T2 series of processors. It was a great performer for web servers and other workloads that were naturally parallel in nature, but wasn't a great performer when it came to single-threaded applications.

If Intel tried to create a processor like this, the fact that software would have to be specifically developed for it to extract its maximum potential would likely end up making it a niche product like the Pentium Pro and the Itanium.

 

[Schmide]

Two words "cache coherency" which I would guess has been driving them nuts with Larrabee.

 

[TurtleCrusher]

Sun produced exactly this type of processor with the UltraSPARC T1 and T2 series of processors. It was a great performer for web servers and other workloads that were naturally parallel in nature, but wasn't a great performer when it came to single-threaded applications.

If Intel tried to create a processor like this, the fact that software would have to be specifically developed for it to extract its maximum potential would likely end up making it a niche product like the Pentium Pro and the Itanium.

That is a beast of a CPU. 8 cores, with each core being able to perform 8 threads at once, with each core able to do two logical threads, that's 128 threads from one processor I'm reading that right, right?

I think Intel could produce something like this for the masses. An Atom with 36-48 threads would be something that could last ages due to multithreaded software becoming the norm. Even at 1.6ghz and 1MB or cache, it's fast enough for most single threaded tasks. Strategy games would be able to seriously prosper and anything that can be processed in parallel would do the same.

 

[Ben90]

I think you fail to realize how slow Atom actually is. Lets do some math right here:

Atom D510 Cinebench R10 Multithreaded: 2024
980X Cinebench R10 Multithreaded: 27056

Your theoretical CPU has 8 D510s stapled together with 100% perfect scaling (Impossible btw)
2024 x 8 = 16192
27056 > 16192


Please don't mention how the 980x is a 1k CPU because its most likely cheaper for them to produce than Nehalem as the die is smaller.

 

[Lonbjerg]

Not to mention the fact that Atom's are In-Order CPU's...not Out-of-Order...

 

[taltamir]

Even though the atom platform itself is pretty slow in comparison to Core 2/Corei3/5/7, I don't understand why intel doesn't produce semi-monolithic Atoms into giant clusters.

they are doing exactly that: http://forums.anandtech.com/showthread.php?t=2078777
its not exactly an atom but its very close... a single die with 48 such chips.

 

[Mothergoose729]

When you get a chip that big with that many parts there starts to be some serious issues with thread scheduling, cache coherency, machine level decoding, ect. Also, an atom processor is about 60mm2, 16 of these processors together would make a very large die even with a very small overall power consumption. Atom itself is not a very efficient architecture, it is merely a very small one.

 

[Fox5]

Atom might make a decent compute product...
But Intel is already offering cpus with 16 threads. I think both among their nehelem derived parts and itanium.
Much better cpus all around, and before long technology will increase enough that they'll be able to shove a ton of their cores on a single die.

 

[TurtleCrusher]

http://www.anandtech.com/show/3768/...-with-512-atom-cpus-and-low-power-consumption

SeaMicro is now putting 512 atom cores into a single box. All using PCI-Express lanes and dedicated 2GB to each PCI-E cluster.

Wow!

 

[Voo]

Two words "cache coherency" which I would guess has been driving them nuts with Larrabee.

Yep, it's not as if you can just stuff 1000 cpus together and hope that you'll get any kind of performance.

And SeaMicros solution has nothing to do with SMPs (or even NUMA) anymore, since every cpu can access only its own 2gb RAM - that may be nice for some niche markets (lots of small servers you don't want to virtualize?), but that's it, it's not as if that was one cluster..