Simple CPU cache sharing question...

[hyrule571]

The cache in a CPU.. is it shared by cores or threads? Idk, im just bored and i feel like asking this question that bothers my mind as im sitting here typing... yeah.

Anyways i was wondering because i just recently bought a Pentium 4 EE 3.2GHz(OC to 3.5GHz) 800FSB(OC to around 875FSB), with 2MB L3 cache. I upgraded from a 3.0GHz P4 with 800FSB and 512KB cache(normally not OC'd because the mobo paried with it was not an OC board and it glitched 3.2GHz+ so i kept it at 3.0Ghz). BOTH have Hyper-Threading, or HT Technology whatever you want to call it. It amazes me that it was a pretty good chunk of a difference this processor made over my old one. So im wondering now if it was that extra cache that made a good difference, and if its shared by cores, in my case i have one on both processors(its a Pentium 4 lolz), or if its shared by the threads(HT creates 2 threads for me yay, when there should have been one =D).. You get it..

 

[ghnader hsmithot]

http://ark.intel.com/Product.aspx?id=27489
considering you have more cache for the pentium and HT yes it would make a massive difference because the cpu wont have to search for the data in the hdd time and again.


And is that cpu of pentium 4 512kb cache a socket 478?

 

[hyrule571]

http://ark.intel.com/Product.aspx?id=27489
considering you have more cache for the pentium and HT yes it would make a massive difference because the cpu wont have to search for the data in the hdd time and again.


And is that cpu of pentium 4 512kb cache a socket 478?

Yes it is a Socket 478 Pentium 4 512KB, with 800FSB at 3.0GHz(HT Technology so 2 threads) processor. Its damaged though, couple broken pins and couple bent ones here and there. How it happened? I was a noob when i was 12 or 13 with computers and i went to look inside my computer and tried learning by myself(which i did accomplish on the hardware for the most part) and i took off the processor and messed with it and just looked at it n stuff.. then glued it on the heatsink with ADHESIVE LOL.. Some stuff that bonds metals ceramics(kinda like super glue but gooey).. 60°C..

**Last question.. Is CPU cache shared by cores or threads? Thanks..

 

[ghnader hsmithot]

yes, all cpu cache is shared by all processing units.Few cpus have their cache have more than 1 independant cache.

 

[ghnader hsmithot]

Why has the shared cache size of the Intel® Core™ i7 processor been reduced compared to the Intel® Core™2 Quad processor?
Although the total amount of shared cache has been reduced for the Intel® Core™ i7 processor, it now has one shared L3 cache vs. two separate L2 caches. The new L3 cache is inclusive which improves efficiency by reducing the amount of snoops needed. A 256K L2 data and instruction cache also has been added to each core of the Intel® Core™ i7 processor, further improving overall cache performance.

http://www.intel.com/cd/channel/reseller/asmo-na/eng/products/desktop/processor/processors/corei7-900/tech/tech_ref/faq/429011.htm

 

[ghnader hsmithot]

Hope it helps!

 

[hyrule571]

Ah i see where your taking this(i think).. So my EE processor has also improved in efficiency because of the L3 cache and now is not stuck only on L2 cache like my other processor was? Well i kinda did get that in the first place...

All CPU cache is shared by all processing units, whats that mean? Cores?

 

[ghnader hsmithot]

yes, cores are actually cpus or processing units.
The correct term is processors but since the modern cpus have more than one core/processing unit we call the modern cpu a cpu but to differentiate the processing units inside a cpu we call it cores.

Some time back we only had 1 processing unit for every cpu.Now we deal with 2 or more.

 

[hyrule571]

Oh i see, kk.. N yes very true, used to be 1, now theres 6 and going on 8 or 10 sooner or later. Quantum computing hopefully will break this core increase every few years and blow away current CPU technology. I've heard of fiber optics processing too but, only God knows =]

Thanks.

 

[ghnader hsmithot]

hope you choose me as your best answer.

 

[hyrule571]

Best answer selected by hyrule571.