dj-ohki wrote:dwchang wrote:
Wow 0 for 3 in the three posts i've replied to.
The Athlon 64 has a 256k L2 cache. I can guarantee you on that. You don't need a whitepaper for that. Just go to any major technical website or vendor.
referenced from
http://www.amd.com/us-en/assets/content ... agram3.gif
128k L1 (64 data, 64 instruction), '1152KB effective cache' (which is where i got the 1mb cache from)
the athlon fx has its own reference page, with
http://www.amd.com/us-en/assets/content ... agram3.gif
note, 128 L1, 1152KB effective. thus, 1meg on each.
uhm...I don't mean to sound arrogant, but I don't blame you since you wouldn't know this.
Nobody in industry talks about "total cache" (which includes the L3). When you talk cache, you talk about the L2 and in both cases, my statements are still correct. You'll notice I explicitely said L2.
FX = 1 MB L2
Athlon 64 = 256k L2
dj-ohki wrote:The Athlon FX has a 1MB L2 cache. Although you are right about the HT links. It only has one while the Opteron has 3. Then again, why would a consumer need more than one 1 HT link which runs at over 4 GB/s xfer on the north-bridge.
6.4Gb/sec, which is 0.8GB/sec. and if the FX is posed to be a prosumer cpu, i would have expected it to have at least 2 HT links (2 way glueless SMP).
Again, the FX still has only one HT link (it even says on that site "
A Hypertransport...). I believe the memory interface is 128 bit though.
dj-ohki wrote:2 MB cache? Are you out of your mind. That would make the die nearly 60% larger than it already it is. Who do you think we are? Intel? People who just throw bigger caches at a performance problem (*cough* Pentium 4 Extreme Edition *cough*).
beacuse the opterion is posed to strike the Xeons, though the 2MB/l2 is prolly from a very old tech spec. but, i would have liked to see a 2MB or even a 8 or 16 MB version of the opertion or 64FX, being memory starved as they are. or perhaps even a 256, 512 or even 1024 bit memory bus when multiple DDR slots are occupided (like nvidia's memory crossbar in the FX video cards). die size be dammed, a 1024bit DDR3200 memory controller in a opeterion core with 8MB L2 would FLY.
Uhm...Memory Starved? Do you understand Computer Architecture? 1 MB of L2 cache is A LOT...well when you consider die-size.
1) L2 increasing has diminishing returns. Sure if you increase it, you get performance, but at a certain point, it's not worth it. The returns just aren't that good.
2) Increasing the L2 will increase the die size. Do you really wanna have a chip *that* big? Oh and go tell the Motherboard manufacturers that they gotta go design *another* motherboard. Yeah right.
3) Increasing L2 size will lead to less yield. L2's aren't that easy to fabricate (or rather large ones). As I said with diminishing returns in performance, you will also get diminishing returns in yield since you won't get that many chips out. Go make an 8 MB L2 cache and see just how many of these (giant) processors will yield at final sort. I doubt even one would out of a possible 250+.
Again, increasing the L2 is just an easy way to increase performance and everyone knows it's the lazy approach. It's *much* better to just make optimizations to your pipeline and various other components. It A) won't increase die-size, B) won't destroy yields and C) will lead to much better performance increases.