4GB versus 8GB of Memory on the Radeon RX 480

Yesterday we took an in-depth look at the new AMD Radeon RX 480 8GB reference card and found that it was a great card for gamers running 1920 x 1080 or 2560 x 1440 displays. The performance was pretty good for a $239 graphics card, but most gamers know that 8GB of GDDR5 memory is overkill if you are just going to be doing 1080P gaming. We had a number of people ask us about how the 4GB card performs since it costs less and $199 is more appealing to them. Let's find out together! AMD Radeon RX 480 Bottom All of the AMD Radeon RX 480 at-launch graphics cards have shipped with 8GB of memory on them. That means if you run out and buy a 4GB card this very second it really does have 8GB of memory on the card. AMD disabled it through a special vBIOS and also lowered the clock speed of the memory on the 4GB cards. [caption id="attachment_183582" align="aligncenter" width="630"]Radeon RX 480 ellesmere XT BIOS Flash Flashing the Radeon RX 480 At-Launch Card To Change The Memory Capacity & Speed[/caption] We got out hands on on both vBIOS revisions and have taken the AMD Radeon RX 480 reference card and have tested with both the 4GB and 8GB versions of the vBIOS! AMD ellesmere XT vBIOS Flash The update process was a simple executable that was run on the desktop that took a few minutes to run and after that we could lock the memory to run at 4GB or run all 8GB. [gallery ids="183578,183579,183577"] For this article we ditched the press driver (Crimson 16.6.2 beta) and installed the public driver (Crimson 16.6.2 WHQL). We also tested at three different configurations to give you the best possible results as board partners will be using both 7Gbps memory and 8Gbps memory on their custom RX 480 cards next month. full-memory With the AMD Radeon RX 480 reference card running the 4GB vBIOS we found that the memory topped out at 3940MHz  when running game titles at a 4K resolution. Before the flash the same game titles were using nearly 6.5GB, so it looks like the memory is being capped. Let's run these three Radeon RX 480 card configurations and see how performance looks on a few benchmarks.

Test System

Before we look at the numbers, let's take a brief look at the test system that was used. All testing was done using a fresh install of Windows 10 Pro 64-bit and benchmarks were completed on the desktop with no other software programs running.  There has been some concern of people testing a cold card versus a hot card, but we've always done out testing 'hot' since the site started back more than a decade ago. Video Cards & Drivers used for testing: Radeon RX 480 Test System

Intel X79/LGA2011 Platform

The Intel X79 platform that we used to test the all of the video cards was running the ASUS P9X79-E WS motherboard with BIOS 1704 that came out on 05/08/2015. We went with the Intel Core i7-4960X Ivy Bridge-E processor to power this platform as it is PCIe 3.0 certified, so all graphics cards are tested with PCI Express Gen 3 enabled. The Kingston HyperX 10th Anniversary 16GB 2400MHz quad channel memory kit was set to XMP Profile #2. This profile defaults to 2133MHz with 1.65v and 11-13-13-30 2T memory timings. The OCZ Vertex 460 240GB SSD was run with latest firmware available. A Corsair AX860i digital power supply provides clean power to the system and is also silent as the fan hardly ever spins up. This is critical to our testing as it lowers the ambient noise level of the room and gives us more accurate sound measurements. Test System Settings Here are the exact hardware components that we are using on our test system:
The Intel X79 Test Platform



Live Pricing

Processor Intel Core i7-4960X
16GB Kingston 2133MHz
Video Card Radeon RX 480
Solid-State Drive OCZ Vertex 460 240GB
Cooling Intel TS13X (Asetek)
Power Supply Corsair AX860i
Operating System Windows 10 64-bit
Monitor Sharp PN-K321 32" 4K
Let's move on to the Battlefield 4 benchmark results!

Battlefield 4

bf4-screenshot Battlefield 4 is a first-person shooter video game developed by EA Digital Illusions CE (DICE) and published by Electronic Arts. It is a sequel to 2011's Battlefield 3 and was released on October 29, 2013 in North America. Battlefield 4's single-player Campaign takes place in 2020, six years after the events of its predecessor. Tensions between Russia and the United States have been running at a record high. On top of this, China is also on the brink of war, as Admiral Chang, the main antagonist, plans to overthrow China's current government; and, if successful, the Russians will have full support from the Chinese, bringing China into a war with the United States. bf4-settings This game title uses the Frostbite 3 game engine and looks great. We tested Battlefield 4 with the Ultra graphics quality preset as most discrete desktop graphics cards can easily play with this IQ setting at 1080P and we still want to be able to push the higher-end cards down the road. We used FRAPS to benchmark with these settings on the Shanghai level. All tests were done with the DirectX 11 API. bf4-vram Benchmark Results: At 1080p resolution we found the AMD Radeon RX 480 8GB was 5 FPS faster on average than the AMD Radeon RX 480 4GB. This comes out to be a 5.8% performance advantage to the 8GB card when running the reference card clock speeds. When we overclocked the memory on the 4GB card up to 8Gbps the performance jumped up and was almost as fast as what we saw on the 8GB card.  bf4-2k-vram Benchmark Results: When scaling the resolution up to 2k (2160×1440) there was only a 3 FPS difference on average betwen the RX 480 8GB and RX 480 4GB, but that comes out to be a 5.8% performance gap from the memory reduction and slower clock frequencies.  bf4-4k-vram Benchmark Results:  When it comes to 4k UHD gaming, the Radeon RX 480 8GB was found to be 6.6% faster than the Radeon RX 480 4GB. We were expecting a larger performance gap at 4K since the memory on the 4GB card was fully used, but there wasn't. 

Fallout 4

Fallout4 Fallout 4 is an open world action role-playing video game developed by Bethesda Game Studios and published by Bethesda Softworks. Fallout 4 is set in a post-apocalyptic Boston in the year 2287, 210 years after a devastating nuclear war, in which the player character emerges from an underground bunker known as a Vault. Gameplay is similar to Fallout 3.  The title is the fifth major installment in the Fallout series and was released worldwide on November 10th, 2015. fallout4 settings Fallout 4 was benchmarked with ultra image quality settings with TAA and 16x AF. These settings are tough for entry level discrete graphics cards, but are more than playable on high-end gaming graphics cards. V-Sync can't be disabled in the games options, so we edited the necessary INI files and disabled vsync in the driver software as well. We used FRAPS to benchmark Fallout 4 after you emerge from the vault and are in The Commonwealth. fallout4-vram Benchmark Results: In Fallout 4, at 1080p resolution, the RX 480 8GB came in at 84.3 FPS, on average, and that was 4.6% faster than the Radeon RX 480 4GB card running the standard reference clock speed of 7Gbps. fallout4--2k-vram Benchmark Results: With the display resolution bumped up to 2160×1440 we saw a 3% performance gap between the 4GB and 8GB cards. Not a huge difference and running the 4GB card at 8Gbps nearly allowed it to catch up to the 8GB card!  fallout-4k-mem Benchmark Results: At full 4K UHD resolution the Radeon RX 480 8GB performed 4.7% better than the Radeon RX 480 4GB with 7Gbps memory. We were really shocked that there wasn't a drop in the minimum frame rate at 4K with the 4GB cards since the dedicated memory was filling up and overflowing to the dynamic memory, but all tests were run three times! 

Far Cry 4

FarCry4 Far Cry 4 is an action-adventure first-person shooter video game developed by Ubisoft Montreal and published by Ubisoft for the PlayStation 3, PlayStation 4, Xbox 360, Xbox One video game consoles, and Microsoft Windows. It is the sequel to 2012's Far Cry 3. The game was released on November 18th, 2014 in North America and Europe. Far Cry 4 follows Ajay Ghale, a young Kyrati-American who returns to his native country Kyrat to spread his deceased mother's ashes. He finds the country in a state of civil war between Kyrat's Royal Army led by the country's eccentric and tyrant king Pagan Min and the Golden Path, a rebel movement fighting to free Kyrat from Min's oppressive rule. FarCry4 settings Far Cry 4 uses the heavily modified Dunia Engine 2 game engine with Havok physics. The graphics are excellent and the game really pushes the limits of what one can expect from mainstream graphics cards. We set game title to Ultra image quality settings and did not adjust any of the advanced settings.   farcry4-1080p

1080P Benchmark Results: In Far Cry 4 at 1920x1080 we found the Radeon RX 480 8GB and Radeon RX 480 4GB cards both running 8Gbps memory had pretty much identical performance. We were shocked to see the Radeon RX 480 4GB card come out ahead, but it was only by 0.1 FPS on average and when doing manual FRAPS runs a tenth of a frame per second is well within the margin of error. The Radeon RX 480 4GB with 7Gbps card came in about 1.5 FPS slower than the cards running 8Gbps memory clock speeds. 


1440P Benchmark Results: Increasing the resolution up to 2560x1440 we found the Radeon RX 480 8GB to be 0.3 FPS faster on average than the Radeon RX 480 4GB when both running 8Gbps memory. Again, this isn't a significant difference in performance. It was great to learn that the Radeon RX 480 could play Far Cry 4 with Ultra image quality settings at 2560 x 1440 and maintain an average frame rage about 60! Pair the Radeon RX 480 with a FreeSync monitor and you'll have a great 2560 x 1600 gaming experience. 


4K Benchmark Results: In Far Cry 4 at 3840 x 2160 we found the Radeon RX 480 8GB and Radeon RX 480 4GB cards both running 8Gbps memory had identical performance whereas the 4GB card with the memory at 7Gbps was not even 1 FPS behind on the average Frame rate.  The memory clock speed doesn't play a big roll in Far Cry 4 nor does having 8GB versus 4GB from what our testing has shown. 

3DMark & Final Thoughts

3Dmark Fire Strike Benchmark Results - For high performance gaming PCs 3DMark is the world's most popular gaming benchmark and graphics card test is used by millions of gamers and overclockers. Fire Strike is a showcase DirectX 11 benchmark designed for today's high-performance gaming PCs. It is Futuremarks most ambitious and technical benchmark ever, featuring real-time graphics rendered with detail and complexity far beyond what is found in other benchmarks and games today. Fire Strike uses a multi-threaded DirectX 11 engine to test DirectX 11 hardware. 3DMark Fire Strike Extreme is an enhanced version of Fire Strike designed for high-end systems. In addition to raising the rendering resolution, additional visual quality improvements increase the rendering load to ensure accurate performance measurements for truly extreme hardware setups.

3DMark Fire Strike

  Fire Strike Extreme Benchmark Results: 3dmark-vram

Benchmark Results: In 3DMark Fire Strike Extreme the AMD Radeon RX 480 8GB card was 3% faster than the AMD Radeon RX 480 4GB card, so you can see while there is a performance difference it really isn't huge in all the game titles. 

AMD Radeon RX 480 Video Card Final Thoughts:  We were very interested in seeing how the AMD Radeon RX 480 would perform with 4GB and 8GB of memory and we were pleasantly surprised with the results. The AMD Radeon RX 480 4GB didn't suffer nearly as bad as we thought it would and with the memory overclocked from 7Gbps to 8Gbps the overall performance of the Radeon RX 480 4GB was very comparable to the 8GB card. The market is flooded with Radeon RX 480 8GB cards right now at $239, but if your budget it tight you might want to wait for one of the more affordable AMD Radeon RX 480 4GB cards at $199. The AMD Radeon RX 480 8GB should also be of interest to those that want to run an AMD CrossFire setup as the larger 8GB frame buffer would likely be more important than here on a single card. If you are worried about performance we highly suggest looking for a Radeon RX 480 with 8Gbps of memory bandwidth as there is a performance difference to be seen between the 7Gbps cards with 224 GB/s of memory bandwidth and the 8Gbps cards with 256 GB/s of memory bandwidth! Let us know if you have any other questions! Our full AMD Radeon RX 480 review can be read here and we also have a news post about how all AMD Radeon RX 480 cards have 8GB of memory at launch than can be read here. We have been kindly asked not to share our vBIOS versions, but we are sure they will turn up online soon enough.