Help me overclock AMD Trinity!

[spacemanc]

Hi! I recently planned a HTPC build to use as a client for MediaPortal. As is often the case, the specification (and cost!) has crept up and it's now going to be a Gaming/HTPC in a very small case. The components are as follows:

AMD A10 5800K Black Edition
ASRock FM2A75M-DGS
Samsung 830 128GB SSD
Kingston 2x4GB 1600MHz LV RAM (KHX1600C9D3LK2/8GX)
Scythe Kozuti Fan & Heatsink
Coolermaster Elite 100 Case & 150w PSU (PSU fan replaced with a Noctua NF-A4x10 FLX)

I plan to do a bit of overclocking/underclocking to fit my requirements of a quiet Gaming/HTPC with maximum graphics performance but high efficiency. I've done a small amount of basic overclocking in the past but I need some advice with this.

1. I went for the 100w A10-5800K instead of the 65w A10-5700, because they're the same chip and cost the same, only AMD have undervolted and underclocked the 5700. I thought that if I get the 5800K I can 'make it' a 5700 if I wish but the opposite would not be possible, so it seemed the best option for flexibility. I don't need much CPU performance but I do need graphics performance, so if possible I want to undervolt and underclock the CPU, but increase the graphics core to 1000MHz

2. Apparently the Trinity APU's get a real boost from memory bandwidth. From reviews that I've read the 1.35v Kingston RAM can be overclocked to 1866MHz @1.575v CL9-9-9-27 or (possibly 10-10-10-27 - the review isn't clear) I've read some Trinity reviews where they have set very loose timings on mediocre RAM to get up to 2133MHz and achieved very nice boosts to graphics performance, so if possible I would like to try for the same.


Has anyone done anything similar? Have I made any 'schoolboy errors' in my thinking or are there any other pointers you guys can give me? The final components arrive on Wednesday and I'd like to hit the ground running with this, so any advice will be gratefully received!

 

[Yuriman]

If you haven't purchased already, get this RAM instead. It runs at way lower timings than its specs suggest. I believe 2100mhz+ isn't unreasonable.

 

[Centauri]

<- Same CPU, motherboard and SSD.

1) I bought the 5800K with the intent of overclocking, but the HSF is nearly worthless. So in the meantime I went the opposite direction; I undervolted at stock frequencies from 1.3875 to 1.3000 and it's solid as a rock. On the GPU front, I OC'd to 950MHz with a slight boost to 1.225v. I could get more out of it with additional voltage, but I'm holding back until I pick out a new HSF (which I want regardless, since this one is also loud in addition to weak)

2) Just get native 1866 RAM - saving $4~ isn't worth the effort of trying to turn 1600 into 1866, especially not when your APU will depend so heavily on your RAM being able to run reliably at that speed. You can get 8GBs of 1866 for under $50. Hell, I got 8GBs of 2133 for less from Patriot at NewEgg. Though, try as I might, I cannot get a stable system at 2133...

 

[spacemanc]

If you haven't purchased already, get this RAM instead. It runs at way lower timings than its specs suggest. I believe 2100mhz+ isn't unreasonable.

I know about that RAM - I'm in the UK and it's hard to buy Samsung green - even harder to find it at a reasonable price.

<- Same CPU, motherboard and SSD.

1) I bought the 5800K with the intent of overclocking, but the HSF is nearly worthless. So in the meantime I went the opposite direction; I undervolted at stock frequencies from 1.3875 to 1.3000 and it's solid as a rock. On the GPU front, I OC'd to 950MHz with a slight boost to 1.225v. I could get more out of it with additional voltage, but I'm holding back until I pick out a new HSF (which I want regardless, since this one is also loud in addition to weak)

2) Just get native 1866 RAM - saving $4~ isn't worth the effort of trying to turn 1600 into 1866, especially not when your APU will depend so heavily on your RAM being able to run reliably at that speed. You can get 8GBs of 1866 for under $50. Hell, I got 8GBs of 2133 for less from Patriot at NewEgg. Though, try as I might, I cannot get a stable system at 2133...

Thanks Centauri that's really useful. I've not dealt with an APU before - in the BIOS I presume you can set individual voltages for GFX core and CPU core? I'm not really sure what to 'play with' in the settings tbh. I do want to keep on top of temps as my case is small and the Kozuti is aimed more at >65w chips really, though it can handle a little more with a noise penalty.

Regarding RAM, again in the UK you tend to see a big step in price when you go above 1600MHz. From the few reviews that I've read of the Kingston RAM I've bought, it looks like it can go to 1866MHz easily with safe voltages and good timings. This is the review that is a little inconclusive on the overclocking figures:

http://www.insidehardware.it/hardwa...1600mhz-memoria-eco-versatile?start=3#content

The system has already started to complete the boot with a voltage of 1.45 V, then an increase of only 0.1 V. However, it proved to be unstable, highlighting the need to relax the timings on the values &#8203;&#8203;10-10-10-27.

With the objective of maintaining the latencies instead of standard frequency 1600 MHz, we pushed the voltage up to 1.575 V (increase of 0.225 V), finding full stability, as well as operating temperatures absolutely fine, we were then allowed to perform the following tests.

I take that to mean that when he increased frequency to 1866MHz, he increased voltages to keep at stock timings, rather than moving to&#8203;&#8203; 10-10-10-27 ? If so then the RAM might be able to hit 2133MHz with looser timings?

To be honest I don't fully understand overclocking RAM as I've never really done it with the aims that I currently have. From what I've read over the past day or two, my understanding is that you increase speed (frequency) but then to make it stable you have to slow down timings (latency) so they cancel each other out to an extent - but a side effect of the increased frequency is higher throughput (bandwidth). Is that right? How do you find the sweet spot?

 

[Centauri]

Yeah, in the BIOS you'll be able to set voltages for basically everything separately including the processor cores and the Northbridge/GPU (it'll be labeled as such). Regarding temp, if AMD OverDrive is to be believed, I'm running 39c across all cores @ my 1.3v after 15 minutes or so of full load.

As far as the RAM, I understand, especially since I myself built this system to a tight budget.

I'm not a master overclocker myself, but your understanding of RAM overclocking is mine as well. Throughput > slower timings in the case of feeding the Radeon component.

 

[spacemanc]

OK well at least I know I'm on the right track. The other slight concern is my 150w PSU. The SSD consumption is negligible and there will be no optical drives, so the only load is Mobo, APU, RAM and Fan. Even so, I'm worried that at peak load it could potentially be pushing dangerously close to 150w maybe? The CPU underclock will help, but GFX always seem to use the most power, so I'm worried that the GFX overclock will cancel that out. I've read reviews for full on gaming PSU's and often the maximum power figures are very conservative so maybe I don't need to worry too much, but 10% on 750w is different to 10% on 150w! (Also bear in mind that the little Noctua on the PSU is less powerful than the stock PSU fan!)

Any idea what your full system loads are Centauri?

 

[ctsoth]

That PSU should be good enough. My llano a8-3870k with 10x low rpm case fans [srsly can't hear them, recycled from old watercooled rig] burns ~150 watts @ 100% cpu and gpu load. You chance of attaining this figure I would think is basically zilch. That said, if I were you I would feel better with a 200w psu. Don't run out and buy anything though, set up your computer and see how it works.

 

[spacemanc]

That PSU should be good enough. My llano a8-3870k with 10x low rpm case fans [srsly can't hear them, recycled from old watercooled rig] burns ~150 watts @ 100% cpu and gpu load. You chance of attaining this figure I would think is basically zilch. That said, if I were you I would feel better with a 200w psu. Don't run out and buy anything though, set up your computer and see how it works.

If anything that is worrying :biggrin: The 3870K is 65w right? - and low RPM fans will be using tiny amounts of power. I expect to be running my underclocked CPU and overclocked GFX at around 100% when gaming. :|

 

[ctsoth]

Gaming won't max out your processor, or really come close in my experience. Simultaneously burning CPU and GPU, via, prime, occt or whatever you like, will drive power consumption higher. Full load system power a8-3870k including loaded igpu = 167 watts. ~25-30 of those watts are gpu alone.

Edit: By max out the processor, I mean total power draw. Not performance or core usage or whatever.

 

[ItsAlive]

I've been interested in picking up Trinity for an HTPC. I was wondering if its possible to disable one of the single cores (not modules) to effectively turn it into a Tri-core, but with the full GPU enabled. It seems like this would negate some of the power used by the CPU and allow for higher CPU or GPU clocking. If my knowledge of the architecture is correct this would also limit the performance hit due to resource sharing in whichever module you disabled the core from.

 

[spacemanc]

I've been interested in picking up Trinity for an HTPC. I was wondering if its possible to disable one of the single cores (not modules) to effectively turn it into a Tri-core, but with the full GPU enabled. It seems like this would negate some of the power used by the CPU and allow for higher CPU or GPU clocking. If my knowledge of the architecture is correct this would also limit the performance hit due to resource sharing in whichever module you disabled the core from.

I doubt this would be possible, because from my limited understanding of Trinity architecture, a lot of resources are shared by pairs of cores?

 

[Yuriman]

If you really have to cut down on power consumption, your only real options are:

1. Underclock/undervolt

2. Return A10, go with an A4, which is a 1 module chip with 2/3 of the GPU hardware disabled

3. Return A10, go with an Ivy Bridge Pentium, which will perform better than the above options and draw something like 15w under load. Add in an HD7750 which has a 55w TDP. It's not a one chip solution though and will probably cost a little more.

I suspect you'll probably be OK with your A10 underclocked though.

 

[sm625]

I just dont see what advantage an A10 has vs something like a 7750 coupled with the even the most dirt cheap celeron.

Additionally, there are dozens of off lease computers you can buy off ebay for $100-$150. Throw a 7750 in any one of those and you have a budget gaming pc much much more powerful than anything you can build anywhere near that price range.

 

[spacemanc]

I'm using a very small case which is not much larger than mITX. Also the PCI-E sockets are inaccessible, so I need to use an APU and Intel APU's suck at graphics which kind of narrows my options to Trinity. An A10-5800K will outperform an i3 graphics + GT 630, so as a package it's a better option. If you go upto an i3 + HD 7750 then you are looking at a bigger budget. Also bear in mind that AMD mobos tend to have a higher spec and yet at the same time, a lower price than the Intel boards.

 

[ctsoth]

You should have good luck undervolting the CPU and simultaneously overclocking the iGPU. The iGPU may need a slight bump to voltage core, but undervolting the CPU should provide you plenty of headroom. I think it likely you can keep system under the 150 watt threshold. a8-3870k is same tdp as a10, but does consume slightly less power at full load. Undervolted full system load is 145 watts for me.