DDR3-800MHz To DDR3-2133MHz Memory Testing With AMD's Kaveri

[misiu_mp]

The timings on the system memory were maintained the same at all frequencies so it's solely a comparison of the memory bandwidth as it impacts the A10-7850K Kaveri APU at its stock frequencies

You mean you kept the timing artificialy high for the lower frequencies instead of using the profiles?

Really Micheal, this truly requires an explanation from you.
Did you mean that you didn't change the timings from their defaults or that you manually set them at the same clock count for all memories (i.e. increasing the timings for the slow memories to the same clock count as the fast memories)?

[mmstick]

@mmstick: Yes, I'm comparing apples to oranges. But the fx-8350 is quite less performant than i5-4670 (here).

@TemplarGR: Yes, good point. However, the difference is 70 euro. Some benchmarks indicate significant differences. I'm planning on using this new computer for as long as possible. The last one lasted 7 years.

@nightmarex: Yes, this benchmark has exposed some limitations. However, I would like to purchase a new CPU/Mobo/Memory *now*. I don't really care about the improvements later on. However, if AMD releases a new FX series this year, I could wait. However, I have read this is probably not going to happen anymore.

Finally, I don't understand the skeptisism regarding to benchmark sites. (What about Phoronix?). It seems, to me, that clock speed has lost it's value as a reliable speed indicator. I prefer to look at benchmarks and CPU extensions.

If I were to look at mHz value's the choice would have been an AMD FX-8350 (8 'questionable'(?) CPU cores) + 1866 mhz memory. However, this setup does not seem perform that well as the clockspeed would indicate. You see this on Phoronix and on other benchmark sites.

Last but not least, a fair competitor of the i7 4770 would be the fx-8350 according to nightmarex (cpu-world) says the i7 is significantly faster. Especially in single threaded performance.

Phoronix is the only reliable source for benchmarks because Windows benchmarks are often compiled in a way that cripples AMD performance, which is well known.

Clock frequency never had any bearing on speed. It's only relevant if compared with the same CPU architecture.

[mmstick]

AMD cpus (modules) are a bit FPU choked by design (double int single fpu), now the actual problems are memory controllers about a gen lower ipc and performance per watt. However your foolish to think AMD cpu's are just cheaper. My 8350 will stomp i7's in some bench's especially when optimized for BD arch. Does it mean it's a better CPU? Not really but I got it for reasons that make it way more appealing than Intels offerings anywhere near the price range of it. Kaveri will beat an i7 with onboard graphics, does that make it a better chip? Not really, unless that's the reason you're buying the fucking thing especially being 100US less.

Actually, those FPUs are two FPUs side by side which can either act as two weaker FPUs or one powerful FPU. Therefore, technically, it's really like having two Phenom II FPUs and two integer units per module. It's more of a problem of big cores versus small cores. Intel uses big cores that are capable of double that of AMDs small core designs. Combined, AMD has more integer power, but should theoretically have the same FPU performance of a quad core i7 with an 8 core FX.

[Rexilion]

The only real difference between Core i5 4670 and Core i7 4770k is Core i5 doesn't have hyper-threading. IIRC the i7 also has a littlie more l3 cache, but that won't affect regular desktop performance that much.

Agreed.

I don't believe you will need more than 4 threads in the near future. And even if you need those, H/T will not make that much of a difference, since those aren't real 8 threads...

This is getting frustrating .

Also, and that advise is for everyone, you should never buy a pc system to last for many years. It is better to buy a cheaper system now, and buy again in 3-4 years.

Not entirely in agreement here. If I buy an i7/i5 now, I'm stuck with the 1600mhz memory + mobo with 1150 socket. There are no indications that newer hardware will be released for this socket. And memory cannot be faster than 1600mhz.

It is not only performance you need, it is compliance with recent standards for cpus and gpus, drivers etc...

The board + CPU I'm picking right now has PCIE 3.0 compliance. That should last for quite a while.

Thanks!

Phoronix is the only reliable source for benchmarks because Windows benchmarks are often compiled in a way that cripples AMD performance, which is well known.

Yeah, I took another look at the fx-8350 here and it's performing quite ok against an intel i7. Although, once again, those cores are not really cores (I have read).

Clock frequency never had any bearing on speed. It's only relevant if compared with the same CPU architecture.

I'll keep that in mind. Although, again, on cpu-world (yes, I will stop using it...) the i7-4771 performs worse than the i7-4770 while the i7-4771 is a whopping 100mhz faster. How is that possible? Is this the reason not to trust these sites?

Thanks!

[tuke81]

I don't think OpenCL automatically uses the HSA paths by default yet, pending further testing & tuning.

Out of curiosity. Does kaveri support OpenCL 2. I thought it adds generic address space which can use hsa. Or are there some vendor side extensions on top of OpenCL 1.2 spec to do the same?


On the topic though, thanks for the test Michael. The impact of memory speed is still huge. It's so sad that some market pcs are sold with 1060MHz memories attached with amds apus. I wonder is there a change to see mobile platform that uses gddr3/5 memories.

[tuke81]

Not entirely in agreement here. If I buy an i7/i5 now, I'm stuck with the 1600mhz memory + mobo with 1150 socket. There are no indications that newer hardware will be released for this socket. And memory cannot be faster than 1600mhz.

Where did you get that 1600MHz? Socket 1150 mobos support memory speeds up to 3000MHz. According to anandtech optimum memory speed is 2400MHz with CL9. Newer hardware update concern might be true though.

[mmstick]

Out of curiosity. Does kaveri support OpenCL 2. I thought it adds generic address space which can use hsa. Or are there some vendor side extensions on top of OpenCL 1.2 spec to do the same?


On the topic though, thanks for the test Michael. The impact of memory speed is still huge. It's so sad that some market pcs are sold with 1060MHz memories attached with amds apus. I wonder is there a change to see mobile platform that uses gddr3/5 memories.

Kaveri is OpenCL 2.0. There are no vendor extensions that I know of as your OpenCL driver handles the translation of OpenCL code to your architecture at runtime.

[djdoo]

@Rexillion

The only real difference between Core i5 4670 and Core i7 4770k is Core i5 doesn't have hyper-threading. IIRC the i7 also has a littlie more l3 cache, but that won't affect regular desktop performance that much.

I don't believe you will need more than 4 threads in the near future. And even if you need those, H/T will not make that much of a difference, since those aren't real 8 threads...

Also, and that advise is for everyone, you should never buy a pc system to last for many years. It is better to buy a cheaper system now, and buy again in 3-4 years.

It is not only performance you need, it is compliance with recent standards for cpus and gpus, drivers etc...

Also you get to have 2 systems for the cost of 1...

Depending on the things you do with your computer, you might not need such an expensive cpu. I am a professional developer and even i don't need a high end cpu... Don't be fooled by marketing. Buy what you need for your needs right now, do not spend more than necessary, and plan only for 3-4 years, then make a new system.

Frequent cheap upgrades are far better than an expensive system every 7 years...

I totally agree with you man! (It is not because we are both from Greece)
So in order to get closer intel's performance in CPU
(current applications not HSA enabled openCL ones, there AMD smashes intel) Kaveri will need all the memory bandwidth it can get, show a set of 2400 Mhz benches will be interesting as michael said in the article but I would suggest even an overclock speed RAM like 2600 or 2666 Mhz to see if they are supported by the Kaveri's memory controller and how they perform.

[profoundWHALE]

If you're talking about a CPU for gaming AND streaming, nothing beats the 8350, and especially for the price.

https://www.youtube.com/watch?v=eu8Sekdb-IE

Those extra 2 cores can be used solely for streaming which is really nice

[Rexilion]

If you're talking about a CPU for gaming AND streaming, nothing beats the 8350, and especially for the price.

https://www.youtube.com/watch?v=eu8Sekdb-IE

Those extra 2 cores can be used solely for streaming which is really nice

I want my new setup to be futureproof, and here are the downside's of the AMD FX 8350:
- No PCIe 3.0 support
- Bad single core performance