Overdrive 3
Of all the overclocking utilities that have been released from manufacturers over the years, AMD’s Overdrive suite is by far our favorite utility for CPU overclocking. With Overdrive 3.0, the best just got better, as AMD is adding Smart Profiles and Black Edition Memory profiles to Overdrive 3.0’s repertoire of features. We’ll start by discussing the latter feature first.
AMD Black Edition Memory Profiles
As NVIDIA and Intel have already done, AMD’s Black Edition Memory Profiles (BEMP) is a feature designed to make it easier for end users to run their DDR3 memory modules at speeds higher than the stock JEDEC standards allow. Rather than having to memorize and manually type in the clock speeds, command rate, tRAS, and other memory timings for your specific memory modules in BIOS, with BEMP all the work is done for you in Overdrive 3.0. AMD has worked with their motherboard partners and memory manufacturers to validate high-end DDR3 memory modules at qualified speeds and timings.
Unlike some of the previous efforts from NVIDIA and others, these settings aren’t actually stored on the memory module, but rather an online database. The profiles for each qualified memory module are stored online as an XML file. When loaded, Overdrive 3.0 simply identifies your memory module(s), and checks the database for a match. If one is found, the proper memory settings are automatically loaded for the user, all you have to do is reboot to apply the new timings. AMD states that by utilizing an online database (rather than say, onboard the memory modules via SPD) they can more easily add BEMP qualified memory modules to the database. The code for the XML profile itself is rather simple too.
Because you don’t have to be a coder to make your own XML profiles, end users can easily make their own profiles if they’d like. Overdrive 3.0 allows you to import and export the files yourself.
In order to take full advantage of the feature, you’ll need a motherboard with proper BIOS support, and qualified memory modules. So far motherboards supported include the ASUS M4A79-T Deluxe, Gigabyte GA-MA790FXT-UD5P, and the MSI 790FX-GD70 v1.0. Qualified memory modules include Corsair’s CM3X2G1600C9DHX, OCZ’s OCZ3AMD18002G, Kingston KHX11000D3LLK2/2G and KHX12800D3K2/2G as well as Mushkin’s 991629. Right now motherboard support for BEMP is limited to 790FX boards, but AMD is working to get the technology validated with more products, obviously since its oriented towards enthusiasts, AMD opted to get the tech up and running with 790FX chipset first, which makes sense to us.
To further optimize performance (and prevent the faster DDR3 memory modules from getting bottlenecked) BEMP will also bump up the North Bridge speed to 2.2GHz in the case of 1333MHz DDR3 modules, and 2.4GHz if 1600MHz DDR3 is detected. North Bridge voltage is also automatically increased by BEMP as well.
Don’t let the name fool you, you don’t need a Black Edition CPU to unlock BEMP, but the feature is limited to the AM3 platform with DDR3 memory. Also keep in mind that you can only run one DDR3-1333MHz (or better) DIMM per channel with AM3. If you max out all four DIMM slots you’re limited to speeds of just 1066MHz officially supported.
Smart Profiles
The other new feature AMD has added to Overdrive 3.0 is Smart Profiles. With this feature, AMD provides custom profiles that will automatically adjust the number of active CPU cores and their clock speeds for optimal performance or power efficiency. You can also use this feature to setup your own custom profiles for games or HTPC applications (say for instance you want to OC your CPU to run Crysis, but underclock the processor to save power/noise when watching a movie).
So far AMD has setup Smart Profiles for the following applications:
3dmark05
3dmark06
MirrorsEdge
Blazing Angels 2
FEAR2
Call of Duty: World at War
Unreal Tournament 3
Dead Space
Quake4
GTA IV
Company of Heroes
Stalker: Clear Sky
Enemy Territories: Quake Wars
Left 4 dead
Call of Juarez
Hawx
Crysis
PCMark05
FEAR
Farcry 2
GRID
Fallout 3
With so many games that are only dual-threaded on the market, Smart Profiles provides a nice option for enthusiasts looking to squeeze every ounce of performance out of their Phenom II processor. Hopefully AMD can build on this feature in the future, including additional parameters such as CPU temperature to dynamically adjust clock speeds and/or number of active cores as well.
Overclocking
Considering our previous OC’ing success with the Phenom II X4 940 Black Edition, we had high hopes for the 955 Black. Fortunately our sample didn’t disappoint.
We managed to clock the CPU at speeds as high as 3.6GHz with stock voltage. That’s over 400MHz higher than the 3.2GHz we hit with our 940 sample. Seeing this, we immediately shot for 4.0GHz, and could actually run some benchmarks at this speed, but couldn’t get the system to run our full battery of stability tests without locking up or generating a BSOD at some point. We did take a nice CPU-Z screenshot though:
Ultimately we had to dial the CPU all the way back down to 3.86GHz (19.0x203.2) in order to gain full 100% stability. We used 1.55V of juice to hit that speed.
We wouldn’t be surprised if we could’ve hit 4.0GHz with a 32-bit OS. We tried to coax the system into running all of our tests at speeds higher than 3.86GHz, but we just couldn’t get all of them to run stable.
All our OC results were run with a Zalman CNPS9700-Cu cooler.