Thursday, June 23, 2016

OC Review: The Gigabyte GA-990FX-Gaming

The buying of a new 990FX motherboard for gaming right now is the height of stupidity. So while this board does offer bells and whistles like Killer Ethernet, M.2, USB 3.1 and an upgraded audio section I will ignore them since these features change absolutely nothing about the fact that 990FX is terrible platform for everything except benching AM3+ CPUs. While this is a "gamer" focused board is does also offer some overclocker goodies like post code LEDs and onboard buttons. As such I'm hoping for it to be a strong alternative as a benching board to the 990FX Sabertooth R2.0 and Crosshair V Formula-Z both of which actually lack some key overclocking features that this board offers. It also helps that Gigabyte's GA-990FX-Gaming comes in at a significantly lower price than the Sabertooth and the Fomula.


- International Rectifier 3564 4+1 phase controller
- 4 phases using IR doublers to make 8

- low side Renesas K0393 rated at 40A @ 25C°(ambient)
- high side Renesas K03B7 rated at 30A @ 25C°(ambient)
- 680nH Inductors
- 12 5K rated 6.3V 560uF capacitors
- 200KHz to 2MHz 
- large VRM + NB + PCH heatsink with 2 heatpipes
- 1 phase using a doubler to make 2
- Renesas K03B7 rated at 30A @ 25C°(ambient)
- 200KHz to 2MHz 
- shares main heatsink
- 2 true phases
- Same MOSFETs as CPU core - No heatsink
- Unknown minimum to unknown maximum KHz

Verdict: 7/10
The VRM on the 990FX-Gaming is strong offering 320A to the core and 80A to the CPUNB as long as you keep the VRM cool. On LN2 that is not a problem as the LN2 pot will be cooling down the entire motherboard. However on air and watercooling the VRM will need some extra cooling because during my short testing with minimal airflow the VRM heatsink was reaching into the 90s with core voltage at 1.55V. Direct airflow from a fan quickly got the temperatures under control however without it I'd expect the IR 3564's OTP to kick and either throttle the CPU or shutdown the VRM. So if you plan to bench this board with an air or water cooler I recommend you stick a fan on the VRM heatsink(which recommend for most AM3+ boards anyway). You might also want consider attaching some small heatsinks on the back side of the PCB in this area:

Maximum Voltages: 
- VCC: 2.3V
- CPUNB: 2.1V
- VDDR: 2.1V
- HTlink: 1.8V
- PCIe: 2.435V
- PLL: 3.135V
- NB: 1.735V 
- 5 Vcore LLC settings
- NB clock from 400 to 6300
- 1 core per CU mode as well as 2 4 and 6 core mode
- XMP Support
- All timings and settings available
- Supports per channel timing settings
- maximum ratio of 10.66X for 2133mhz at 200mhz FSB
- core unlocking on Phenom II and Athlon II CPUs 
- 8 onboard BIOS profiles and option to store profiles on USB stick or SATA drive
Verdict: 9/10
The BIOS uses the standard Gigabyte layout. All the voltage limits are high enough that even with LN2 cooling you can kill anything and everything you could install on this motherboard. The VRM settings however are a little lack luster. There are no switching frequency, response time or current limit settings like you would find on an ASUS board and you only have LLC settings for the core voltage. The core voltage LLC settings are also pretty bad with Everything but the medium and extreme setting dropping far too much voltage to be useful. The medium setting is perfect for daily usage and even benchmarking since it idles at the voltage you set and drops only 20mv going under load. The extreme LLC setting on the other hand provides a huge amount of voltage boost going under load and as such is useless for daily use and I wouldn't use it even when benchmarking just because of the 80mv voltage spread it has. Memory overclocking on the 990FX-Gaming is on the tedious side especially when pushing above 2133mhz as the board does not have a 12x ratio. So in order to get any memory clock above 2133mhz you need to start messing with the FSB. That's not really a major issue if the board showed you the impact of FSB on the NB and HT link speeds but it doesn't so regardless of your FSB setting you will only ever see the NB ratio * 200. Of course you need to run your NB above your memory clock so you just need to use the 11x NB ratio when using the 10.66X memory ratio but it would still be nice to see what the actual NB speed is going to be. Other than that memory overclocking on the board works perfectly well and the board recovers from crashes quickly without trashing your settings so you don't even have to save overclock profiles every time you change something even though I do recommend doing that just in case the board doesn't manage to recover properly from an extra bad mix of settings that require a BIOS wipe. Overall the BIOS on the 990FX-Gaming has everything I want and need when overclocking and is easy to navigate after you get used to Gigabyte's layout.

Air Testing Results:
Max RAM speed (FX 9590 + 1 4GB stick): DDR3-2603 13-16-16-36-2T 1.75V
PSC best settings(FX 9590 + 2 2GB sticks): DDR3-2500 8-12-8-28-2T 1.83V
1600mhz low timings(Phenom II X2 555BE): 1600 5-7-5-18 1.9V
Max FX 9590 validation clock 2 cores with 1.65V: 5222mhz
Max CB11.5 core clock with 1.55V: 4950mhz
Max FSB: 320mhz
Verdict: 9/10
Gigabyte may only rate the board to do 2000mhz on the RAM and the highest RAM multiplier is only 10.66x however with a bit of tweaking I got the RAM as high as 2603mhz. More is probably possible however with AM3+ compatible CPUs your NB clock needs to be equal or greater than the RAM clock and as such maximum frequency ended up limited by the North bridge which needed to be on a 11X ratio to stay ahead of the RAM speed. This is not ideal as it forces your NB clock to be a few 10s of mhz higher than the RAM speed which makes you run into NB stability problems that much sooner.
My FX9590's Norhtbridge showed just how bad it is when I did my PSC testing. The kit is capable of doing 2600 8-12-8-28-1T on a little over 1.86V. My FX 9590 on the other hand is absolutely incapable of dealing with much more than 2400mhz with such low timings without giving the north bridge a lot of voltage. In the end I managed to get the system to just barely finish SuperPi 32M with 2500 8-12-8-28-2T with 1.83V on the RAM and 1.45V(too much to be safe on air or water) on the North Bridge. Since it's my CPU that's holding the RAM back I'm gonna say that the board handles high performance RAM just fine you just need a capable CPU.
Now some of you maybe wondering about why I do a 1600mhz low timing test. The test exists because most Phenom II and Athlon II CPUs can't go much beyond 1600mhz RAM clock so to get good memory performance it is important to be able to get really low timings at speeds between 1450 and 1650mhz. I'm happy to say that the 990FX-Gaming didn't have any problems doing 5-7-5-18 timings however the board can't go bellow 5 so if you have a kit of RAM that can pull of 1600 at CL4 you're out of luck.
The 990FX-Gaming manages the same maximum core clock at 1.65V as my Sabertooth did. However the software for the Gaming is a lot more painful to work with. Gigabyte's Easy Tune require's Gigabyte's App Center software which requires .NET 4.5 and really didn't like my stripped down win 7 install. So I had to go and make a new install of windows to get Easy Tune to work. Considering that I remember having similar issues with AIsuite so it's not like Gigabyte's obnoxious OC software is anymore obnoxious than ASUS's I'd still prefer a stripped down utility however I do understand that since no one really cares about AM3+ any longer that there isn't a slim OC utility for it.
For cinebench clocks the 990FX-Gaming matches the Sabertooth exactly so again no complaints from me.
Maximum FSB varies from motherboard to motherboard and maxing it out completely is very time intensive. A high maximum FSB is very important when benchmarking CPUs with locked multipliers like the Athlon II X3 460 or a Sempron 145. The Gaming getting an easy 320mhz is inline with what the Sabertooth does which is inline with most 990FX boards. They generally start having issues going above 330mhz on the FSB and as such the Gaming is not inferior to any of them in this department either.
Unfortunately even with the great overclocking results I can't give the 990FX-Gaming a 10/10 here because I've never tested any of the boards that are priced above the Sabertooth and they may deliver better results than this board.

Conclusion: 25/30 Points, 0.179pts/$(based on Amazon price at the time of writing)
Gigabyte's 990FX-Gaming makes for a great AM3+ overclocking board. Personally I prefer it to my deceased 990FX Sabertooth R2.0 and I'm not saying that just because the Saberooth decided to die on me. The fact is that Gigabyte's BIOS offers more features than the Sabertooth's. All the voltages you need are accessible and can be pushed higher than on the Saber. This is especially true of the Gigbayte's Vcore setting which goes all the way to 2.3V compared to 2.075V on the Saber. That's enough voltage to quickly kill FX chips even with LN2. The Gigabyte board also offers core unlocking on Phenom II and Athlon II chips which the Sabertooth R2.0 nor Formula-Z offer. You also get dual BIOS as well as on-board buttons both features that the Sabertooth lacks. In testing the Gaming managed the same results as the Sabertooth and recovered much more smoothly from bad settings than the Saber ever did. This board is however not perfect. The VRM is slightly weaker than the Saber's and while still plenty power full for water or LN2 cooling it requires direct airflow at high voltages and loads which the Sabertooth doesn't need as long as you just have decent airflow in your case. Overall I like the Gigabyte better than the Sabertooth between the buttons, the dual BIOS, the core unlocking and the lower price the Gigabyte is both less hassle to work with, better featured and cheaper than the Sabertooth and from my aircooled testing you don't seem to lose any performance for any of these benefits. Other than that the 990FX-Gaming also offers a bunch of "gamer" features that the Saber also lacks. Really if this board had been available when I was buying my Sabertooth and I weren't a massive ASUS mobo fan I would have probably taken this instead because it's just better and cheaper. So if you're looking for a relatively cheap motherboard for benchmarking ALL(you can't convert X2s to X3s on the Saber or Formula-Z!) AM3+ CPUs the 990FX-Gaming is one of the best out there. Oh and you can use it to play games I guess... if that's your thing.

As soon as I get my LN2 Dewar topped up again I will do another live-streamed 8+Ghz attempt with the 990FX-Gaming and after that it will be featured for any AMD CPU benching I do until AM4 boards launch.

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