Why are the APUs CPUs so slow but have great GPU?

[FatRakoon]

I may be barking up the ignorant tree here, and heck, I usually am, but I only have 2 of the AMD APUs.

A4 3300 - 2.5Ghz Dual Core.
A10-6800K - 4.1Ghz Quad Core.

Now, the A4 was the first one I pplopped together, I just needed to knock up a basic Media PC and I saw a nice bundle for a nice price and thats the direction I went.

I had a nice play about, and I loved it. it was great fun to play about with it, and I even bought a compatible GFX card to do the Hybrid Graphics with it and it plays a surprising number of games. Not the top end stuff of course, but all the same, it does play things it should not.

The CPU side of things however, is bloody rubbish.

I expected a lot more performance from a 2.5Ghz Dual core, but putting it mildly, I did not get anything more than a wheezy athsmatic budgie with heavy shopping level of performance. I was thoroughly underwhelmed.

Now, my daughter is using that PC, but she only really does basic internet and watching TV etc, so she is fine with that.

More recently, I was twiddling about with the idea of knocking up an ITX PC for no other reason than I am bored, and so after looking around on various places, I saw a mobo and CPU that looked nalf decent for a price I was ok with, and so I grabbed it. the MM here gave me a lovely ITX case to plop it into and the rest of the bits I have lying about and so thats sorted that out.

Now, the CPU is much much better than the A4 was, but its still lacking in actual grunt. There is simply nothing really there?

Its a 4.1Ghz Quad core and I would have seriously expected a lot more than what this is giving me.

I have done a few simple little tests and I have compared it to the 8350 at one core and at 4 cores, and then of course giving the 8350 all its cores just for a maxed out comparison ) and on 1 and 4 cores, the A10 is not too far away from half the speed of the 8350.

I dont have the numbers in front of me, but I converted a video file from MKV to MP4 and with a single core on the 8350, it took 7 minutes and whatever seceonds and the A10 took 12 minutes and such and such seconds... Almost twice as long!

It was a similar story when I did the same test but used 4 cores.

The speeds were stock, so 4.0Ghz on the 8350 and 4.1 on the A10

Now, this is a ame, because graphically, it is not at all bad. Radeon 8670D Graphics, so its actually useable performance.

But why have a half decent graphical ability yet a fairly junky CPU speed?

As I said, ignorance seems to be on the menu for me at the moment, but thats how I feel it is so please correct me if I need to be.

 

[FatRakoon]

AMD are using an archaic CPU architecture and depending on the GPU side to keep them in some relevance until they can push out ZEN etc.

The current APU's / CPU side are just very weak, ok for budget PC build, media player etc. But for any actual gaming, an Intel CPU plus cheap DGPU is the way forward. At least until we see what Zen is capable of etc. Intel have the i5 5675C / i7 5775C which are also an APU in all but name (CPU + GPU), much better than AMD's current APU's. Maybe look to one of them as an alternative.

No, no, I dont think you understand me.

My main PC is a Skylark, and the 8350 is my main Linux PC. I have only knocked up the A10 purely for a giggle and nothing more.

As Cheesyboy says, barring a smaller Cache, the CPU core should be the same as the 8350 and therefore the speeds should be about the same ( 4.0 v 4.1 ) but in the test that I gave them, no they were not.

Could I have accidentally been using 2 cores thinking I was on one with the 8350?

I would say no, but you have me thinking now and so I will double check and re-do some tests to be sure.

 

[FatRakoon]

In my case, the original A4 that I got, was purely down to a combination, of requirement and cost.

I was knocking up a Media PC, and I was looking to do it cheaply, but I was not willing to be silly and go for a Celeron.

The A4 was a ridiculously cheap CPU, and the performance of the Graphical side of it, was surprisingly good, and so yes, in order to get better, I would be spending another £50 or so more, just for a GFX card to add to it. Therefore, the choice of this chip, to me, seemed to be fairly obvious.


And intels onboard graphics dont even come close to what I have seen on the AMD CPUs - I have not done any real or true tests I will freely admit, but, to make the claim that they would have been a better choice, is something that I am unable to grasp.

The A10 was no different.

Graphically, I am very happy with it. I dont need it to play top of the range games, and I am using it for a Linux PC and so sure, I have plenty of Steam games and I also use Wine and so a few games I would love it to play.
I have also, even gone out and bought another Radeon card compatible with its dual Graphics purely for a laugh, and a play about, even though I have much faster cards lying about doing nothing, but again, its just to toy about with this hybrid crossfire / dual graphics - I know that its not going to be any quicker than any number of other cards I already have, but thats not the point of why I do these things. Im just bloody bored and so that is why I do it most of the time.

I have not got round to re-trying any tests because I have a lovely setup of Linux in that PC now, I have tried upping the BIOS a few times on the A10 cos its on the Factory one and I have a newer one to use, and it has failed to go in a few times now ( Thank god for Dual bios and recovery LOL ) and yet, I have done the FaceWizard sillyness and given it a rather childish and ego boosting Linux boot logo. when I plop Windows back on, I wioll no doubt have yet more attempts at doing the BIOS, and a better ego stroker pic too of course.

 

[FatRakoon]

Well, I am doing some extra junk to make doubly sure, that I have not made a mistake.

What I have done, or I am doing, is converting an AVI or a complete movie that is 2GB in size.

I am using Format Factory and with one single core, converting it to an MKV and resizing to 320x240

I am doing this on both the 8350 and the A10

The 8350 has finished. It took 38:32

The A10 is still working on it.

Now, I left it a minute or so, and the A10 is still at 72% and so, I decided to give it another go with the 8350, but this time using all 8 cores, and simply converting to MKV but no resizing... Dont know why I did this other than to get the max convertion.

It completed it in 13:19 and a quick peek at the A10 shows me that its still at 78%

So lets wait....

Ok, the A10 has finisahed now, at the time that took was 54:20


So, on a single core, thats 38:32 for the 8350 and 54:20 for the A10

I did go into the BIOS, but I was unable to find any option to force it to run on a single core, and so, this is simply with forcing the program to only use one core, with the Task Manager... This was also verified by the task manager as only using the one core when I started the convertion.

So again, on the systems I have, the 8350 is clearly showing that even on single core, it is much faster than the A10 - 54vs38 is more or less about a third faster give or take?

 

[FatRakoon]

I think the motherboard BIOS might be throttling the A10,or its overheating.

Look at comparisons of the A10 6800K and the FX4300:

http://www.guru3d.com/articles_pages/amd_a10_6800k_review_apu,14.html

hmmm.

Well the Motherboard that I am using, is a Gigabyte F2A85XN-WIFI and as of 15 minutes ago, it has the latest BIOS ( F3a ). I dont know about it throttling the CPU... I dont think it is... Its not at all slow and its incredibly responsive in everything I ask it to do... I have only really seen it underperform to what I ecpected it to, when converting fims from X to Y and seeing as I use my main PC for that anyway, its almost a mute subject in all honesty.

As for overheating, again, this is not the cause. I am running a Seidon 120 and it has 2x120mm fans, one either side of the rad, and the water block itself isnt any warmer than stone cold,, and SpeedFan shows me 26c up to a max of 33c under load.

 

[FatRakoon]

8 cores vs 4 - also are you using gpu accelleration to help with the transcoding which will help even things out.

for video encoding 8350 is a beast.......A10 is good; but it will be slightly slower as its only a 4 core; but normally can help off load some if it by using igpu......

I've built several apu machine and love them....but for super heavy lifting stuff I tend to use my 8320e at 5.0 ghz....

I simply wanted to compare them both, core for core.
I forced the convertion to only run on one core, to get an idea of how they compared.

Sure, I have also done some messing about with using the GFX to help out, why the heck not. It does make a difference of course.

And no, I have run the 8350 with all cores against the A10 with its 4, purely to show the total speed differences, but Im not taking that too seriously.

The A10 is absolutely snappy, it really is, and in fact, I am using it right now, I have put the Linux HDs back in and Im back on Lionux again and its a really nippy little bugger and I simply cannot fault it.

The thing is, that I expected it to be roughly on par with the 8350 core for core because at stock they are both so close in speed, but from what I am getting, it simply is not.

5Ghz? - nice one. I get 4.7 with relative ease, and when I used the G.Skill, I got it very easily indeed with just the automatic tune in the BIOS, but I have since bought 32GB of TeamElite and its rubbish junk that hates me clocking anything at all, and so 4.3 seems to be its limit no matter what else I try? - I gave up and now I run it at stock, and thats absolutely fine because its not my main PC.

 

[FatRakoon]

you sure it was a single core; as those scores sound like 8 vs 4; as one on one there will be some difference as there is no L3 on the A10; as there is on 8350. Core wise there is no speed difference between the two as they are the same core.

L3 could be the difference; or something is screwy with your set up as if we look at 4300 vs 6800k; similar speeds; they score within % points of each other........8350 4 more cores really stretches its legs in things like this.

Yea I'm going to switching out H80i for aircooler as temps aren't all that stable at times at 5 ghz.....I've put her back down to 4.6 for now

Ok, I may have offered some confusion there...

When I was doing the actual serious tests, as there does not seem to be any way that the 8350 can be forced to a single core in the BIOS, instead, I have simply used the Task manager to do it, on the APP that I am using to convert the files with.

The 8350 Motherboard is the Sabretooth 990FX and I was sure that this board can do it, but I have failed to find it.

The Board that the A10 is in, does indeed have that option, however in order to keep things as close to fair as I can, I have also used the task manager to force it to only use the one core.

So, yes, I have only used the one core for doing the tests.

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Now, I did also use the 4 cores of the A10 and the 4 and then 8 cores of the 8350 PURELY just to see how much faster, the 8350 could do the job than the A10 could, but that was purely to know... Naturally, as seems to be the case, using 4 cores, the 8350 should be about the same as the A10, and using all 8 cores should be double that of the A10, when the A10 uses all 4 of its cores... These are just mpy even close to the results that I am seeing at all.

 

[FatRakoon]

Aye, the issue was not the 990 board but the little one.

fairly limited in what you can and cannot do.

But yes, the cache is going to be the difference.

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Small note. In the last post, I have just re-read and I have said about the 8350 and the 990FX but I have them completely back to front... The limitation is with the small ITX board and not the 990

That is clearly going to let out some confusion and I appologise for that.

I am doing a lot of messing about, not just with those 2 boards, but I also have a laptop that I have been twiddling about with comparing an I5 with an I7 and also I am tuning up a mates PC as well, and so I am working on half a dozen things qat once, and so I am getting some stuff mixed up. I have just fried my old I7 Laptop I think with all the overclocking and sodding about I have been pushing her through, ( lots of lols there ) and so yeah, Im well mixing myself about, so again... Appologies.