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Intel kicking AMD to the curb?
Tatsujin:
So considering that Core i7 has a small L Cashe (someone typed that from above) ... would it affect the processor or the speed it's choking on?
kyanwan:
--- Quote from: kureshii on July 22, 2009, 10:07:27 AM ---In fact, now that I check, AMD Phenom II X4 955 has double the L1/L2 cache of Intel Core i7 920, but less L3 (6MB on 955 vs 8MB on 920). Q9550 has half the L1 and double the L2 size of the X4 955.
--- End quote ---
I just looked at that and ...
Why the hell did someone give it a 1? That person needs to be smacked. XD
--- Quote from: Tatsujin on July 22, 2009, 05:41:54 PM ---So considering that Core i7 has a small L Cashe (someone typed that from above) ... would it affect the processor or the speed it's choking on?
--- End quote ---
Cache is for pre-loading of code, predictive processing, and routines used by programs often. It would speed up the program/threads currently in execution to have more cache available to it. ( More code loaded directly in the CPU = much faster execution. On-CPU cache is bounds faster than main memory. )
Depending on how the CPU handles it / manages it - it can have a performance effect.
Obviously, Intel is handling it right - because there are no performance problems. You see the benchmarks - those answer your question on "smaller" = "worse performance". ( I see, that generally - Intels have a bigger cache than any AMD - go figure. )
NOTE though - the "code" to operate this, is hardwired INTO the CPU - it's "physical" - as in AND, XOR, and NAND gates burned right there in your CPU's silicon.
I'd also like to point out - that compared to the processors of long ago - the on-CPU caches we enjoy today - are GIANT - I'm talking we had in the past 64, 128, and 256K - if you were lucky. 1 & 2mb CPUs were over $1K ... in the not too distant past.
Lupin:
Bigger cache is always better, especially cache that are much closer to the cores (L1). A larger cache means you can cram more data into it, reducing the time your processor needs to access your main memory. It will add to the cost of the processor though.
kureshii:
--- Quote from: Tatsujin on July 22, 2009, 05:41:54 PM ---So considering that Core i7 has a small L Cashe (someone typed that from above) ... would it affect the processor or the speed it's choking on?
--- End quote ---
From benchmarks, seems like it's not that big a concern yet ::)
How much cache you can fit on a particular processor die really depends on how much space you have left after putting in the other stuff.
Techreport.com
That's an image from techreport showing the i7's die. Notice how much space is taken up by the 8MB L3 cache. There isn't much space for each core, let alone to squeeze in even 256kB of L2 cache (in the bottom-right corner of each core, I think). Intel's new direction for multi-core processors is to have smaller L1 and L2 caches (trying to find the exact article on Anandtech where they quote this from an interview with one of the Intel guys), and larger L3 caches instead. Here's an old link to Anandtech discussing this.
Large L1/2s make sense for processors with fewer cores, but as you scale up the number of processors you'll increasingly find that they need to access information that is only available on the caches of other cores (generally speaking, the L1/2 cache of each core is not accessible to the other cores. There are some exceptions, like the Core 2 Quad series where L2 was shared between 2 cores).
Accessing information on another core's cache takes a long time, so a more sensible solution would be to have a larger shared L3 cache, and smaller exclusive L1/2 cache. This explains why they made the L3 cache inclusive (i.e. L3 also contains data stored in L1 and L2).
--- Quote from: kyanwan on July 22, 2009, 05:54:10 PM ---Why the hell did someone give it a 1? That person needs to be smacked. XD
--- End quote ---
Most people who rate stuff 1 on Newegg are people who got DOA parts, lol. Dunno about his particular case; some of them are failed overclockers who vent their frustrations on Newegg, too.
kyanwan:
--- Quote from: kureshii on July 23, 2009, 12:53:11 AM ---
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I've so got to write another CPU emulator. Just for the hell of it.
( * Did something on the lines of a 4004 back in college - as an EE project. )
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