Articles: CPU
 

Bookmark and Share

(62) 
Pages: [ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 ]

Overclocking

Socket FM1 platform wasn’t particularly overclocking-friendly. Llano processors had low overclocking potential, increasing the frequency of the base clock generator would often cause instability, there were few supported dividers for the memory frequency. Overall, AMD didn’t really encourage overclocking of their previous generation APUs, so even their proprietary Overdrive utility wasn’t really optimized for them. But their attitude to overclocking has changed a lot with the launch of the new Socket FM2 platform and the APU for it. Now overclocking functionality is one of the official strengths of the hybrid processors. And in this respect, Trinity processors are indisputably better than the competing Core i3, which cannot be overclocked at all.

Overclocking-friendliness of the Socket FM2 platform manifests itself in many aspects. Namely, there are a lot of processor models with unlocked frequency multipliers, which are marked with a letter “K” in the model name. However, even overclocking by simply raising the base clock generator frequency should be fairly easy. In most cases, it can be increased by up to 80% above the nominal without losing system stability. The only two things to keep in mind in this case are: first, significant increase in the clock generator frequency causes mainboard D-Sub out to stop working; and second, to ensure that there are no disk sub-system issues in AHCI mode, you have to use the AMD driver instead of the default Microsoft driver from the OS suite. Here we also have to add that there are a lot of memory dividers available, and the fact that the poor Overdrive utility has finally started to work with hybrid processors.

All above mentioned overclocker improvements are purely theoretical. In reality, computer enthusiasts obviously expect Trinity to demonstrate increased overclocking potential, because they are based on Piledriver microarchitecture, Bulldozer’s successor, which is capable of working at pretty high frequencies.

However, we failed to achieve any remarkable results during our overclocking experiments. Yes, Trinity, just like Bulldozer, is very sensitive to computing core voltage increase and the stability threshold is pushed back every time to take another step higher. However, the heat dissipation also increases dramatically, which requires extra-ordinary cooling solutions. At the same time, it is almost impossible to monitor the acceptable thermal conditions. Thermal sensors integrated into the previous AMD processor cores have never been particularly precise, but in case of Trinity they are nothing short of a catastrophe. For example, in moments of idling they can easily report temperatures close to 0, and under light operational loads they would often show temperature readings below the actual room temperature. Therefore, we had to use the temperature readings taken off the mainboard diode, which is extremely inertial.

Anyway, we managed to overclock our A10-5800K processor with the NZXT Havik 140 cooler to 4.5 GHz in the testbed built on ASUS F2A85-V Pro mainboard. However, this is not maximum overclocking, but the frequency, at which the system is operational in 24/7 mode. To ensure stability in this mode we increased the processor Vcore by 0.15 V above the nominal reaching 1.5 V.

So, in terms of resulting clock speeds, Trinity overclocking is very similar to Bulldozer overclocking. Similar microarchitecture provides similar overclocking potential. The use of a principally different platform doesn’t affect the results in any way.

The primary distinguishing feature of the Trinity processors is the ability to overclock not only its computing part, but also the graphics core. And I have to say that this is a pretty logical scenario for integrated systems in its practical aspect. Graphics accelerator integrated into the Trinity processors works almost as fast as discrete Radeon HD 6570 and overall is not the dream come true just yet. Therefore, many advanced users who will decide to go with a Socket FM2 processor will most likely want to overclock their graphics. And it will pay off to some extent. However, it is also important to remember that overclocking system memory could also help improve 3D performance of the graphics core in Trinity processors, so it can definitely compliment the straight-forward increase in the graphics core frequency.

During our experiments we managed to get the Radeon HD 7660D graphics core in our A10-5800K processor to work stably at 1085 MHz, which is 285 MHz higher than the nominal frequency. Note that to ensure successful overclocking like that, you should respectively increase the corresponding voltage, which in the mainboard BIOS is usually referred to in as voltage of the North Bridge integrated into the processor, but in reality to also applies to the graphics core. In our specific case it was increased from 1.175 V to 1.4 V.

Together with the graphics core overclocking, we increased the memory frequency to the level of DDR3- 2400. This is the maximum memory mode for Trinity processors working at the nominal base clock generator frequency. To ensure stability the only thing we had to do was to set Command rate to 2T.

Let’s take a look at the following screenshot showing our overclocking success:

By overclocking our computing cores, graphics core and memory we managed to score over 2000 points in 3DMark (with Performance profile). This way, the graphics performance of our A10-5800K based system increased by about 25% and reached the level of a discrete Radeon HD 6670 compared with the nominal graphics performance of the same processor. Not bad, don’t you think so?

However, the overclocking of the computing part alone seems to have no obvious practical value like that. By comparing the Physics Score results we can show that increasing the clock frequency of our A10-5800K to 4.5 GHz produces only 11% boost in computing power. AMD has set the clock frequency of their new Trinity processors high enough right from the beginning, so only extreme cooling methods will allow boosting the overclocked performance significantly. For example, according to the manufacturer, the use of liquid nitrogen should enable Trinity processors to reach frequency as high as 6.5 GHz, but there is evidence that AMD A10-5800K has already conquered 7.3 GHz speed.

 
Pages: [ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 ]

Discussion

Comments currently: 62
Discussion started: 10/01/12 10:18:21 PM
Latest comment: 10/13/14 02:46:17 AM

View comments

Add your Comment