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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AmdInside - Wednesday, October 12, 2011 - link
Their roadmap is aggressive but when is the last time AMD has come close to meeting their schedule? Not going to happen. But do hope that they do for consumers sake.Eagle70ss - Wednesday, October 12, 2011 - link
AMD really bent over and grabbed their ankles....I'm just wondering why it took so long to release douche-dozer...I was really hoping they would have a good part this time...Will Intel stand alone as the sole quality CPU maker?? Only time will tell, but it looks to be so....silverblue - Wednesday, October 12, 2011 - link
I must say, I did expect this. That price drop wasn't exactly a giveaway, was it? Single threaded performance is generally poor and there really is something wrong with the caching. I simply refuse to believe a lack of BIOS optimisations is at fault for any of this... and blaming Windows 7 for not truly understanding Bulldozer's idiosyncracies? Come off it; Windows 8 won't even be around when Piledriver appears, and we'll have to wait to see the second generation of this particular microarchitecture performing more like it "should". Bringing back the FX moniker certainly attracted attention, however if by doing so they wanted to remind us of the fact that the FX-51 was a server CPU, they've succeeded, if only on that basis, as the FX was king of all and not just in select benchmarks as the P4 tended to be.I can't wait for Johan's server review; I just want to see if this thing really does well in its natural habitat. It's got to have a success somewhere. Thankfully, I can see far more optimism in this area. Incidentally, I was expecting Bulldozer to be able to work on eight 128-bit FP instructions per clock as opposed to 6 with Thuban, so obviously I got my wires crossed on that one.
You can't argue that Bulldozer hasn't a lot of promise, but at the same time, you can't argue that AMD haven't been trying to perform damage limitation on an already faulty product.
arjuna1 - Wednesday, October 12, 2011 - link
Nobody, and I mean, nobody at all, expected Bulldozer to reach SB like performance, obvious nobody either saw sub Phenom II performance in certain applications, but almost everything promised has been delivered, at lower prices than Intel, the way AMD has always done it, and quoting the article:"In many ways, where Bulldozer is a clear win is where AMD has always done well in: heavily threaded applications. If you're predominantly running well threaded workloads, Bulldozer will typically give you performance somewhere around or above Intel's 2500K."
PS
wolfman3k5, stop your Intel shilling, it almost look like if Intel was paying you by the hour.
wolfman3k5 - Wednesday, October 12, 2011 - link
I get $22.50 per hour from Intel plus tips. I also get a $50.00 bonus if I surpass 1000 comments / posts per day. Between 3:00AM and 7:00AM I get $25.85 per hour. I make good money writing nice things about Intel. What do you do?g101 - Wednesday, October 12, 2011 - link
What's surprising is that you apparently think that's "good money".Guess what, you little dumbshit kid, profit savvy professionals will sill be running AMD. I couldn't care less about your shitty lightly threaded games and optimized synthetic benchmarks.
Stupid children using their computers for play.
silverblue - Friday, October 14, 2011 - link
You need to bear in mind that a) AMD reintroduced the FX brand just for Zambezi, and b) JF-AMD actually started a thread entitled The Bulldozer Blog Is Live! on www.overclock.net. Regardless of whether John Freuhe is a server-focused guy or not, the point being is that he and AMD both targetted the client side in terms of i) overclockers and ii) gamers. I might be wrong, but that's how I see it. Yes, he didn't come out and say it directly that Zambezi would be a great gaming solution, but he DID say that IPC would be an improvement over their past products. Now that the reviews are out, he's nowhere to be seen, barring the odd login to do who-knows-what. Does overclock.net have any leaning towards the server market in any way?If Zambezi's poor performance is partly down to using faulty ASUS boards/anything less than 1866MHz RAM/an L1 cache bug/some weird hardware combinations/WHATEVER, I'm sure we'll find out in time, but regardless, it's going to be harming non-gaming workloads as well, so it's important to people like you as well.
silverblue - Friday, October 14, 2011 - link
Just thought I'd say that I've been a bit harsh to JF there. Out of all the AMD people who could've come along to have a chat, he was definitely the bravest. It was on his free time, and he's probably getting copious amounts of hate messages just for being an AMD rep.Proxicon - Wednesday, October 12, 2011 - link
I stayed up all night to read this review....I guess the prices on 2600k won't be going down anytime soon. I had already built my complete system in my head. Then the reviews came..
I kind of figured that if AMD was firing people and resignations were being handed in before a major launch, it wasn't going to be good. Also, no early release of benchmarks. That in itself was suspect. If they really had such a great processor than why all the secrecy. I was hoping it was an Apple play. boy, was I wrong.
You guys buy the "faildozer" and help keep the prices of the 2600K low. I'll be looking for a 2600K....
3DVagabond - Wednesday, October 12, 2011 - link
I'm not an expert, but Bulldozer seems to be a server chip pressed into desktop service. Designed for highly threaded workloads many consumer tasks just aren't it's forte (and also designed to have even more cores than 8). While it isn't competitive in single thread performance, if you use highly threaded workloads enough and aren't afraid to O/C to boost the single core performance, Bulldozer can be the better chip. That is if the price is right. The 8120 might be an awesome value in this scenario. We'll have to wait for reviews to be sure.One question, please. When you O/C'd the 8150, did you only use stock cooling? From the review it sounded like you did, but instead of saying so clearly, you said it wouldn't do 5GHz on "air" (I believe that was the statement? Feel free to flame me if I'm wrong. :D). So, to be clear, would it not do 5GHz on air with a top notch cooler, or did you only try the stock cooler?
Thanks.