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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saneblane - Thursday, October 13, 2011 - link
Man, you have a lot of optimism. I am a big Amd fan, but even i can remain optimistic after this mess, I mean how do you make a chip that is slow, expensive and losses to it's older brothers. Barcelona was a huge success compare to this, it only seemed bad because Expectations were high, this time around though they became higher because no one expect Amd to actually go backwards in performance. WOW that's all i can say WOWPipperox - Thursday, October 13, 2011 - link
I don't understand why you all think it's slower than its older brothers.It's not, it's faster than Thuban in practically all benchmarks...
Or do you really care about stuff like SuperPi?
Pipperox - Thursday, October 13, 2011 - link
But maybe you guys think that it's slower "clock for clock" or "core for core".It doesn't matter how you achieve performance.
What matters is the end performance.
Bulldozer architecture allows it to have higher clock speed and more *threads* than Phenom.
The penalty is single threaded performance.
Again you can't compare it to an hypothetical 8 core 4.0GHz Thuban, because they couldn't have made it (and make any money out of it).
I'll repeat, the FX-8150 is NOT an 8-core CPU.
Otherwise the i7-2600K is also an 8-core CPU... both can execute 8 threads in parallel, but each pair of threads shares execution resources.
The main difference is that Sandy Bridge can "join" all the resources of 2 threads to improve the performance of a single thread, while Bulldozer cannot.
They probably didn't do it to reduce HW complexity and allow easier scalability to more threads and higher clock speed.
Because the future (and to a large extent, the present) is heavily multithreaded, and because Bulldozer is targeted mainly at servers. (and the proof is its ridiculous cache)
bryman - Thursday, October 13, 2011 - link
how about some bios screenshots? Is there a way in the bios to disable the northbridge in the chip and use the northbridge on the motherboard? Possibly better performance, or maybe add a new ability to x-fire northbridges? (Yah imah Dreamer). imo, I dont think adding the northbridge to the cpu was a good idea especially if it pulls away from other resources on the chip, I understand what adding the northbridge to the processor does, but does it turn off the northbridge thats already on the motherboard? The northbridge on the chip makes sense for an APU but not for a perfomance CPU, why is the nothbridge even in there. I myself would rather see the northbridge on the motherboard utilizing that space intstead of the space on the cpu.If there isnt a way to turn off the northbridge on the cpu in the bios, i think the motherboard manufactures should include the ability to turn off the northbridge on the cpu. Add the ability to use the onboard northbridge in there bios, so you can atleast get bios or firmware updates to the northbridge and perhaps get more performance out of the cpu/gpu.
When the new Radeon 7000 series video cards come out, if I buy this CPU with the 6000 series northbridge in it, am I going to take a performance hit or am i going to have to buy a new processor with the 7000 series northbridge in it? or will they come out with a 7000 series motherboard that utilizes a 7000 series northbridge that turns off the 6000 series northbridge in the chip, which in turn makes it useless anyways. I myself dont like the fact if i buy this product, if i want to upgrade my northbridge/ motherboard, I might have to buy a new processor/ perhaps a new motherboard or am i just paranoid or not understanding something.
Who knows, maybe in the next couple of weeks, Mcrosoft and/or AMD will come out with a performance driver for the new processors.
If they would have come out with this processor when planned originally, it really would have kicked butt. instead we get conglimerated ideas over the five year period, which looks like the beginning idea, thrown into a 2011 die.
I am i die-hard AMD fanboy and always will be, Just kinda dissappointed, excuse my rants. I will be buying a 4 core when they hit the streets, hopefully in a couple weeks.
saneblane - Thursday, October 13, 2011 - link
From the caching issues, to the bad glofo process, to the windows scheduler, i recon that this processor wasn't ready for prime time. Amd didn't have any choice i mean they almost took an entire year extra for peet sake. Even though my i5 2500 is on it's way, am not stupid enough to believe this is the best the arch can do. Their is a good reason that interlagos cannot be bought in stores, Amd know for a fact that they cannot sell this cpu to server maker, so they are busy working on it, i expect that it might take one or even 2 more stepping to fix this processor, the multithread performance is their so they only need to get a mature 32nm process to crank up the speeds and maintain the power consumptions. IMOarjuna1 - Thursday, October 13, 2011 - link
Reviews @ other sites like toms hardware and guru 3d are starting to make this look bad. How come everyone but Anand got to review it with watercooling?? Is this site in such bad terms with AMD?B3an - Thursday, October 13, 2011 - link
Water cooling isn't magically going to help performance or power consumption in any way so why does it matter?? When you buy this CPU it comes with air cooling, and Anand was right to use that for this review.marcelormt - Thursday, October 13, 2011 - link
http://www.tomshardware.com/reviews/does-amds-athl...Patrick: The 6000+ is the fastest Athlon 64 X2 dual core processor ever, but what happened to the FX family?
Damon: Patrick, you are right. The X2 6000+ is the fastest AMD64 dual-core processor ever... so why isn't it called FX? To answer that I have to explain what FX is all about... pushing the boundaries of desktop PCs. FX-51 did that right out of the gate, with multiple advantages over other AMD processors, and a clear lead on the competition. Move forward a bit to where AMD put high-performance, native dual-core computing into a single socket with the FX-60. Fast forward again and you see FX pushing new boundaries as "4x4" delivers four high-performance cores with a direct-connect, SLI platform that is ready to be upgraded to 8 cores later this year
Ryomitomo - Thursday, October 13, 2011 - link
I'm a little surprised you only posted Win7/Win8 comparison figures for FX-8150. It would give a much complete picture if you would also post i7-2600k Win7/Win8 comparison.czerro - Thursday, October 13, 2011 - link
I think anand handled this review fine. Bulldozer is a little underwhelming, but we still don't know where the platform is going to go from here. Is everyone's memory so short term that they don't remember the rocky SandyBridge start?