Overclocking Galaxy’s GTX 750 Ti GC Slim without Limits

Test Configuration – Hardware

• Test Configuration – Hardware
• Intel Core i7-4770K (reference 3.5GHz, HyperThreading and Turbo boost is on to 3.7GHz; overclocked to 4.0GHz; DX11 CPU graphics), supplied by Intel.
• ECS GANK Domination Z87H3-A2X motherboard (Intel Z87 chipset, latest BIOS, PCOe 3.0 specification, CrossFire/SLI 8x+8x) supplied by ECS

• Kingston 8 GB HyperX Predator DDR3 PC2800 RAM (2×4 GB, dual-channel at 2400MHz for Ivy Bridge and 2800MHz for Haswell, supplied by Kingston)
• Galaxy GTX 750 Ti GC Slim, Galaxy factory overclock and also further overclocked, on loan from Galaxy
• GeForce GTX 750 Ti, 2GB reference clocks and also further overclocked, supplied by Nvidia
• Nvidia GTX 650 Ti, 1 GB reference design and clocks, supplied by Nvidia
• Sapphire Vapor-X HD 7770 1050/1400MHz factory overclocked and supplied by Sapphire
• PowerColor R9 270X PCS+, 2GB stock speeds, supplied by PowerColor
• Two 2TB Toshiba 7200 rpm HDDs
• Thermaltake ToughPower 775W power supply unit supplied by Thermaltake
• Thermaltake Water2.0 Pro watercooler, supplied by Thermaltake
• Onboard Realtek Audio
• Genius SP-D150 speakers, supplied by Genius
• Thermaltake Overseer RX-I full tower case, supplied by Thermaltake
• Philips DVD SATA writer
• HP LP3065 2560×1600 thirty inch LCD

Test Configuration – Software

• Nvidia GeForce 334.69 launch drivers. Also GeForce 335.39 WHQL for removing overclock limitations.  High Quality, prefer maximum performance, single display.
• AMD 13.12 WHQL Catalyst drivers; latest CAPs. High Quality – optimizations off; use application settings for HD 7770/R9 270X and for R9 290x.  Catalyst 13.11 used for all other Radeons.
• Windows 7 64-bit; very latest updates
• Latest DirectX
• All games are patched to their latest versions.
• VSync is off in the control panel.
• AA enabled as noted in games; all in-game settings are specified with 16xAF always applied; 16xAF forced in control panel for Crysis.
• All results show average, minimum and maximum frame rates except as noted.
• Highest quality sound (stereo) used in all games.
• Windows 7 64, all DX10 titles were run under DX10 render paths; DX11 titles under DX11 render paths.

The Benchmarks

Synthetic

• 3DMark 11
• Firestrike – Basic & Extreme
• Heaven 4.0

• The Witcher 2
• Borderlands 2
• Aliens: Colonial Marines

• Crysis

• STALKER, Call of Pripyat
• Civilization V
• Max Payne 3
• the Secret World
• Sleeping Dogs
• Sniper Elite V2
• Hitman: Absolution
• Far Cry 3
• Tomb Raider: 2013
• Crysis 3
• BioShock: Infinite
• Metro: Last Light
• GRID 2
• Splinter Cell: Blacklist
• Total War: Rome II
• Batman: Arkham Origins
• Assassin’s Creed IV: Black Flag

Before we get to the Galaxy GTX 750 Ti’s performance charts, let’s look at overclocking, power draw and temperatures.

Overclocking, Power Draw, Noise and Temperatures

Overclocking the Galaxy GTX 750 Ti GC Slim is just as easy as overclocking any other GTX 700 series card. Our Galaxy GTX 750 Ti GC Slim edition is already overclocked +52MHz over the Nvidia reference clocks. We were able to overclock a further +135MHz with complete stability even though we did not adjust the voltage nor our fan profile. We also managed +600MHz on the memory clocks which were respectable and 50Hz higher than we could reach with the reference version.

The main limitation to overclocking the GTX 750 Ti is that the software is limited in the drivers to a maximum offset of +135MHz.  This means that our maximum boost was 1337MHz, a substantial jump over the reference Ti’s clocks Boost of 1284MHz.

Fortunately, on Monday, the day that we expected to publish this review, Nvidia released new WHQL drivers that remove the +135MHz maximum clock offset.  We were able to gain another +25MHz to reach a maximum Boost of 1361Mhz.

Removing TDP limitations

We also used a BIOS that was modded by CryptoMiningBlog.com that removed the TDP limitations as it returned the GC to factory clocks.  However, bearing in mind that the GC is clocked +52MHz higher than the reference version, we were able to offset +220MHz on the (now reference clocked) core with the modded reference BIOS, or +8MHz higher with the TDP limitations removed than with them in place.

What was particularly interesting is that the benches run at 1369MHz Boost with the TDP limitations removed have significantly higher performance than an 8MHz gain from 1361MHz would normally bring and  they can easily be seen in the performance summary charts.  We also found more stability with the voltage left at stock.

Even with overclocking further, temperatures generally stayed below 75C and the fan rarely exceeded 55%. Because of it’s custom fan design, the Galaxy GTX 750 Ti GC Slim is a quiet card, even quieter than the very quiet reference version.

For our testing of the Galaxy GTX 750 Ti, we usually move the temperature target to its maximum 90C. In this way we do not allow lack of power nor moderate temperatures to throttle performance. Likewise, we also max the PowerTune slider for AMD cards.  However, in this case, the temperatures settings never “stick” and they always default back to 80C.

Let’s head to the performance charts to see how the Galaxy GTX 750 Ti GC Slim compares with the reference GTX 750 Ti.