The graphics processing unit, or GPU is responsible for performing the bulk of graphical operations.
GPUs differ from CPUs in that they tend to contain vast amounts of weaker cores while CPUs have far less cores, although each of them are very powerful. This difference means GPUs are great for tasks that can be performed in parallel. As a result, graphics cards are capable of producing 3D graphics at a much faster rate than CPUs, which make them ideal for gaming and video rendering.
If you are building a system for gaming, it is recommended that you devote the largest chunk of your budget towards getting the most powerful graphics card you can afford as this will (in most cases) have the greatest impact by far on your gaming performance.
Graphics cards connect to the motherboard via PCIe (Peripheral Component Interconnect Express) ports. Most GPUs will require additional PCIe power cables that will be provided by the power supply unit.
Unlike CPUs, the same GPU model can have custom PCBs and cooling designs on them which vary between vendors.
For example, an RTX 2060 from MSI will differ from an RTX 2060 from ASUS. One might run hotter or louder than the other, and in many cases vendors are known to make serious design errors on their cards that lead to unsafe temperatures or loud noise. Because of this, it is important that you look at reviews for the specific card that you want to buy.
These GPUs mostly target the 1080p 60Hz resolution, with the RX 5600 XT and RTX 2060 pushing into 1440p 60Hz territory.
Although a previous-gen part from 2017, the RX 570 maintains a solid price to performance ratio for those on an extreme budget.
GTX 1650 Super
A good value proposition from NVIDIA on the low end. Performance is comparable to an RX 580/GTX 1060.
GTX 1660 Super
This is arguably the best value option in its market segment, with performance between the RX 590 and GTX 1070.
RX 5600 XT
A competitive GPU from AMD with performance on par with the RTX 2060 and priced a hair below it.
Higher priced than the 1660 Super but another solid budget option, with performance close to a GTX 1080.
These GPUs can easily do 1440p 60Hz and are good choices for 1440p 144Hz or 4K 60Hz gaming.
Radeon RX 5700
A great value card for 1440p. It is priced between an RTX 2060 and 2060 Super with performance on par with the latter.
The adventurous can try BIOS flashing this card to unlock it to a 5700 XT.
Radeon RX 5700 XT
Another great value card for 1440p. It is priced similarly to a 2060 Super but offers performance around 10% below the far more expensive 2070 Super.
RTX 2070 Super
This delivers solid performance for its price, for those looking for an NVIDIA GPU or ray-tracing features.
These GPUs target 4K and high-refresh 1440p gaming.
RTX 2080 Super
Priced one tier below the 2080 Ti, the 2080 Super is the strongest performing GPU that is also at least somewhat reasonably priced.
RTX 2080 Ti
The best performing GPU by far, with an incredibly high price tag to match.
ASUS ROG Strix RTX 2080 Ti - The best, horribly overpriced consumer grade card and the best aftermarket cooler. The Strix is efficient at cooling and a very silent cooler relative to the competition. The fans turn off completely at low temperatures.
(I'll finish this later - Sabine)
This section was last edited on 12/06/2020.
NVIDIA vs AMD (Opinionated)
The two main competitors in the graphics card market are NVIDIA and AMD. NVIDIA has the highest performing GPUs at the high end (by a significant margin), but AMD usually has more competitive offerings around the mid range and low end.
NVIDIA cards tend to be more power efficient and generate less heat, although AMD has all but closed the gap with their RDNA architecture.
Software and Features
With the release of the RTX 20-series cards, NVIDIA cards have more specialised hardware for video encoding which significantly improves their performance in this regard over AMD.
NVIDIA and AMD have counterparts for some of each other's software:
- For adaptive sync, AMD Freesync works well on any monitor with HDMI/DisplayPort. NVIDIA G-Sync used to require specialised, expensive G-Sync monitors, however this has changed and NVIDIA GPUs now support Freesync monitors, although stability is an issue in a few cases.
- NVIDIA ShadowPlay functions similarly to AMD's Radeon ReLive.
- NVIDIA Ansel (a photography tool that can be used in-game) has no counterpart on the AMD front.
- Ansel has very limited support on games, however - only a handful will work with it.
- NVIDIA's DLSS (Deep Learning Super Sampling) is similar to AMD's RIS (Radeon Image Sharpening).
- DLSS must be implemented on a per-game basis, while RIS works globally - although DLSS 2.0 tends to produce better results when it does work.
- NVIDIA's Ultra-Low Latency Mode works essentially the same as Radeon Anti-Lag.
- NVIDIA's new RTX technology has no counterpart yet on the AMD front, although AMD's upcoming RDNA2 architecture scheduled for late 2020 will include hardware ray-tracing support.
- AMD's Radeon Chill significantly lowers heat output and power draw of the GPU by reducing framerate when no fast movement is occuring on the screen (which makes the framerate reduction very hard to notice).
- NVIDIA does not have an alternative to this.
- AMD's Radeon Boost dynamically decreases render resolution when fast movements are occuring on the screen, sacrificing image quality for performance. Due to the fast movements, the reduction in image quality is harder to notice.
- It's worth noting that this feature only works on a per-game basis, so support across games is limited.
This section was last edited on 12/06/2020.
Video RAM (or VRAM) is specialised memory located on the card, dedicated to storing image data such as textures and shaders.
Having sufficient VRAM is essential for running higher resolution textures in games without incurring a performance penalty.
For 1080p gaming, 6GB of VRAM is usually good enough.
For 1440p gaming, 8GB is a safer choice.
Coolers consist of a heatsink and fans that dissipate heat from the GPU, memory and other components on the card. It is recommended that you buy a card with a good cooler if you wish to overclock, as overclocking creates higher temperatures.
It is recommended that you avoid "blower" graphics cards, which include the reference design cards produced by AMD, and NVIDIA (before the RTX 20-series). These are usually the first releases of any new card. They use a blower style cooler in place of the usual open air cooler that aftermarket brands ship with. These are typically far less effective and often result in higher temperatures and louder noise.
It is a good idea to frequently update your GPU drivers. You can download these from the website of the GPU manufacturer (AMD, NVIDIA, or Intel).
Driver updates frequently fix bugs, improve overall performance or add compatibility with new game releases.
AMD and NVIDIA also provide useful features with their drivers, such as Radeon Chill or NVIDIA's DLSS.
Overclocking and Undervolting
Just like CPUs, graphics cards can be overclocked. The performance gain from overclocking varies by GPU model, but a recent trend is that GPUs will intelligently boost their clocks when necessary. As a result, overclocking on newer generation cards provides less of a performance gain over stock settings.
Overclocking a card too much can cause instability and crashes. Overvolting the card can stabilise an otherwise unstable overclock, but will increase the heat generated by the card (and power usage). At a certain point, thermal throttling (decrease in performance caused by high temperatures) will counteract the performance gains from overclocking, so having a good cooler will allow you to overclock further before this limit is reached.
Setting up a custom fan profile can help to lower noise at lower temperatures or increase cooling at higher temperatures.
The recommended overclocking software is currently MSI Afterburner, although owners of AMD GPUs can use the inbuilt tools in Radeon Software to do this.
After overclocking a card, it is important to test that your overclock is stable using games or benchmarking software such as Unigine Superposition or 3DMark Time Spy. Be sure to run these for at least half an hour and watch out for any artifacts (visual glitching), crashes or instability.
Lowering the voltage on GPUs (while maintaining the same clock speed) can improve heat, noise, power draw and (to a very small extent) performance.
Typically AMD GPUs benefit much more from this than NVIDIA ones, one example being the RX 5700 series cards.