The Bulldozer Review: AMD FX-8150 Tested
by Anand Lal Shimpi on October 12, 2011 1:27 AM ESTCache and Memory Performance
I mentioned earlier that cache latencies are higher in order to accommodate the larger caches (8MB L2 + 8MB L3) as well as the high frequency design. We turned to our old friend cachemem to measure these latencies in clocks:
| Cache/Memory Latency Comparison | ||||||
| L1 | L2 | L3 | Main Memory | |||
| AMD FX-8150 (3.6GHz) | 4 | 21 | 65 | 195 | ||
| AMD Phenom II X4 975 BE (3.6GHz) | 3 | 15 | 59 | 182 | ||
| AMD Phenom II X6 1100T (3.3GHz) | 3 | 14 | 55 | 157 | ||
| Intel Core i5 2500K (3.3GHz) | 4 | 11 | 25 | 148 | ||
Cache latencies are up significantly across the board, which is to be expected given the increase in pipeline depth as well as cache size. But is Bulldozer able to overcome the increase through higher clocks? To find out we have to convert latency in clocks to latency in nanoseconds:
We disable turbo in order to get predictable clock speeds, which lets us accurately calculate memory latency in ns. The FX-8150 at 3.6GHz has a longer trip down memory lane than its predecessor, also at 3.6GHz. The higher latency caches play a role in this as they are necessary to help drive AMD's frequency up. What happens if we turn turbo on and peg the FX-8150 at 3.9GHz? Memory latency goes down. Bulldozer still isn't able to get to main memory as quickly as Sandy Bridge, but thanks to Turbo Core it's able to do so better than the outgoing Phenom II.
L3 access latency is effectively a wash compared to the Phenom II thanks to the higher clock speeds enabled by Turbo Core. Latencies haven't really improved though, and Bulldozer has a long way to go before it reaches Sandy Bridge access latencies.
Facebook
Twitter
RSS
430 Comments
View All Comments
Fujikoma - Wednesday, October 12, 2011 - link
Really... in this day and age... 'jewing'???bji - Wednesday, October 12, 2011 - link
Yeah I stopped reading his comment exactly at that word. Disgusting.eh_ch - Wednesday, October 12, 2011 - link
You could try to argue that describing the performance as retarded *might* be syntactically and grammatically correct, but clearly it's meant in the pejorative sense. You could have pointed out the ironic misspelling. But you didn't react at all.Idiots.
bji - Wednesday, October 12, 2011 - link
Sorry, but 'retarded' has already entered common usage and isn't offensive to anyone not looking explicitly to be offended.'Jewing' however has not, not even close.
EnerJi - Wednesday, October 12, 2011 - link
I beg to differ. It very much is offensive to anyone who has a friend, family member, or other person they care about with a mental handicap.g101 - Wednesday, October 12, 2011 - link
What do you expect? The majority of these comments come from idiot children that only care about games and completely misunderstand the point of this architecture.Hrel - Wednesday, October 12, 2011 - link
ya'll need to lighten up and take life less seriously. If you're wasting your time being politically correct then you're wasting your time... nuff said.Hrel - Wednesday, October 12, 2011 - link
I disagree, jewing is totally not offensive. My friends call me jewish all the time and I'm not really any religion AND I'm mostly German. It's just joke dude, lighten up.Hrel - Wednesday, October 12, 2011 - link
I like to spell retarted that way better, that's how I say it. I also spell theater theatre and ever since that movie Inglorious Baterds and I spell bastard basterd. I just like it better.Hrel - Wednesday, October 12, 2011 - link
what's disgusting is that you're so racist it offends you. If you truly aren't racist then it doesn't matter. It's just another way of saying being cheap. And as long as you're not a pent up old politically correct fogey it's humorous.