Lower Power, Same Performance
AMD is in a strange position in that there is a lot of excitement about their upcoming Zen architecture, but we are still many months away from that introduction. AMD obviously needs to keep the dollars flowing in, and part of that means that we get refreshes now and then of current products. The “Kaveri” products that have been powering the latest APUs from AMD have received one of those refreshes. AMD has done some redesigning of the chip and tweaked the process technology used to manufacture them. The resulting product is the “Godavari” refresh that offers slightly higher clockspeeds as well as better overall power efficiency as compared to the previous “Kaveri” products.
One of the first refreshes was the A8-7670K that hit the ground in November of 2015. This is a slightly cut down part that features 6 GPU compute units vs. the 8 that a fully enabled Godavari chip has. This continues to be a FM2+ based chip with a 95 watt TDP. The clockspeed of this part goes from 3.6 GHz to 3.9 GHz. The GPU portion runs at the same 757 MHz that the original A10-7850K ran at. It is interesting to note that it is still a 95 watt TDP part with essentially the same clockspeeds as the 7850K, but with two fewer GPU compute units.
The other product being covered here is a bit more interesting. The A10-7860K looks to be a larger improvement from the previous 7850K in terms of power and performance. It shares the same CPU clockspeed range as the 7850K (3.6 GHz to 3.9 GHz), but improves upon the GPU clockspeed by hitting around 800 MHz. At first this seems underwhelming until we realize that AMD has lowered the TDP from 95 watts down to 65 watts. Less power consumed and less heat produced for the same performance from the CPU side and improved performance from the GPU seems like a nice advance.
AMD continues to utilize GLOBALFOUNDRIES 28 nm Bulk/HKMG process for their latest APUs and will continue to do so until Zen is released late this year. This is not the same 28 nm process that we were introduced to over four years ago. Over that time improvements have been made to improve yields and bins, as well as optimize power and clockspeed. GF also can adjust the process on a per batch basis to improve certain aspects of a design (higher speed, more leakage, lower power, etc.). They cannot produce miracles though. Do not expect 22 nm FinFET performance or density with these latest AMD products. Those kinds of improvements will show up with Samsung/GF’s 14nm LPP and TSMC’s 16nm FF+ lines. While AMD will be introducing GPUs on 14nm LPP this summer, the Zen launch in late 2016 will be the first AMD CPU to utilize that advanced process.
Subject: Editorial | April 24, 2014 - 01:51 AM | Josh Walrath
Tagged: TDP, Athlon 5350, Asus AM1I-A, amd, AM1
If I had one regret about my AM1 review that posted a few weeks ago, it was that I used a pretty hefty (relatively speaking) 500 watt power supply for a part that is listed at a 25 watt TDP. Power supplies really do not hit their efficiency numbers until they are at least under 50% load. Even the most efficient 500 watt power supply is going to inflate the consumption numbers of these diminutive parts that we are currently testing.
Keep it simple... keep it efficient.
Ryan had sent along a 60 watt notebook power supply with an ATX cable adapter at around the same time as I started testing on the AMD Athlon 5350 and Asus AM1I-A. I was somewhat roped into running that previously mentioned 500 watt power supply due to comparative reasons. I was using a 100 watt TDP A10-6790 APU with a pretty loaded Gigabyte A88X based ITX motherboard. That combination would have likely fried the 60 watt (12v x 5A) notebook power supply under load.
Now that I had a little extra time on my hands, I was able to finally get around to seeing exactly how efficient this little number could get. I swapped the old WD Green 1 TB drive for a new Samsung 840 EVO 500 GB SSD. I removed the BD-ROM drive completely from the equation as well. Neither of those parts uses a lot of wattage, but I am pushing this combination to go as low as I possibly can.
The results are pretty interesting. At idle we see the 60 watt supply (sans spinning drive and BD-ROM) hitting 12 watts as measured from the wall. The 500 watt power supply and those extra pieces added another 11 watts of draw. At load we see a somewhat similar numbers, but not nearly as dramatic as at idle. The 60 watt system is drawing 29 watts while the 500 watt system is at 37 watts.
So how do you get from a 60 watt notebook power adapter to ATX standard? This is the brains behind the operation.
The numbers for both power supplies are both good, but we do see that we get a nice jump in efficiency from using the smaller unit and a SSD instead of a spinning drive. Either way, the Athlon 5350 and AMD AM1 infrastructure sip power as compared to most desktop processors.