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.
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arjuna1 - Wednesday, October 12, 2011 - link
I was wondering the same, the OC part of the review seemed rushed by, almost lazy, I hope Anand can correct this and clear the doubts, can one of this cpus be run @ 5ghz or not?silverblue - Wednesday, October 12, 2011 - link
Anand did say that he doesn't yet possess one of the AMD sanctioned water coolers, but will test with it once he does.arjuna1 - Wednesday, October 12, 2011 - link
More of the reason to have considered in testing it with an aftermarket cooler, if it hits 5ghz only with AMD's sanctioned cooler (which given the insignificant difference between Corsair and Antec offerings wouldn't surprise me if it was just a rebrand) it can be a bit of a problem to those of us already using a similar water cooler.arjuna1 - Wednesday, October 12, 2011 - link
they have it on legitreviews running @ 4.9 with water cooling.silverblue - Thursday, October 13, 2011 - link
HardwareHeaven have theirs at 5.2.Jkm3141 - Wednesday, October 12, 2011 - link
I would LOVE to see how this handles a virtual server workloadJohanAnandtech - Wednesday, October 12, 2011 - link
Patience :-). We will do our best with a new virtualization benchmark besides the old one when the Interlagos server arrives.- Johan.
ghosttr - Wednesday, October 12, 2011 - link
Not only does CPU fail, it fails so hard it even struggles to compete with its aging predecessors. A new architecture AND a die shrink and it can barely hold its own.Whats really sad is that AMD could have updated k10, and probably achieved the same (or likely better) results.
bersl2 - Wednesday, October 12, 2011 - link
I'll probably end up buying one. I'm still on my socket-939 Opteron 165, and I can wait a little bit more. Since many of you seem to be wont to skip this one, I'll probably get it at a better price.Also, since I don't give a flying fsck about Windows, I'll probably get a Bulldozer-aware CPU scheduler before you clowns do. :P
Hrel - Wednesday, October 12, 2011 - link
Seriously disapointed now. I'm glad they put more than 2 freaking SATA 6GB ports on the mobo, but that's a 200 dollar+ mobo so it doesn't really matter.AMD's CPU performance is retarted. Honestly, all the hype, all the delays, this is a disaster. Good thing their GPU division is executing well or I'd be seriously worried about this company being around in 4 years.
Intel needs to stop jewing out on their mobo configurations. I need AT LEAST 4 SATA 6GBPS ports and I was like 12 USB 3.0 ports, but even with my gripes about them cheaping out on mobo's and switching sockets every year or two... at least their CPU's have gotten faster in the last 6 years. Beyond just expected incremental gains like AMD has made.... or this time around hasn't.