When we buy a new video card, we usually only check the type of GPU present and the amount of video memory dedicated to it, ignoring other fundamental parameters to be able to fully evaluate the power of a graphics card. Among these parameters, the type of video memory certainly stands out, which in certain situations can make the difference between a game faithfully reproduced with a high number of details. Let's see together the various types of video memory available at the moment and the performance differences between it, so you can choose the next video card also observing this type of parameter.
The newer technologies obviously cost more, but we can find fast video memories also integrated in cheap video cards, just check the product data sheet carefully.
READ ALSO -> How to choose the video card for PC graphics
1) What is video memory for?
Video memory is an important component of graphics cards (both integrated and dedicated), given that it temporarily stores all the graphic information processed by the processor or waiting to be processed; it behaves in a very similar way to the RAM of the computer, but it is much faster and is optimized for storing any type of video information (from the graphic engine to the management of the polygons of each element present in a game).
It goes without saying that more video memory translates into more storable details, but we must not underestimate the speed aspect: if the video memory is too slow, the GPU will slow down in turn, "waiting" for the memory becomes free or is ready to accept new video data.
That's why between a video card with only 4 GB of memory but with very fast chips and one with 6 GB of memory but with slow chips, we must prefer the card with the faster memory, because it will be freed sooner and will be much more responsive in storing new information inside it (the 6GB card will be fine only until it becomes saturated, at which point the slowdowns will begin).
Currently it is possible to find two types of video memory inside the graphic cards: GDDR and HBM ; let's see in detail what both technologies offer.
2) What is GDDR
GDDR is the most common abbreviation to identify the video memories present on the same card where the GPU is present; in the past, in fact, video processors had to exploit a part of the RAM memory (the normal one of the PC) to be able to store video data, but the latency was really too high (the temporary video data had to leave the GPU, go to the motherboard, enter the RAM and, once requested, perform the reverse path).
To speed things up, it was decided to place the memory chips around the GPU, with a new technology very similar to DDR RAM but optimized to accommodate video data at much higher speeds.
Also thanks to this technology the spectacular games that we have seen in these years have arrived, in particular those with numerous details on the game background or with many active characters on the screen.
Currently the commercially available versions of GDDR are GDDR5 (most of the NVIDIA video cards up to the GTX 1070), GDDR5x (NVIDIA GTX 1080 and 1080Ti) and the new GDDR6 (NVIDIA RTX 2060, 2070 and 2080).
When we purchase a new video card produced by NVIDIA we make sure that one of these types of video memory is present, so as to always have maximum performance; instead we avoid video cards with obsolete versions of GDDR, DDR3 video memory or with video memory shared with system RAM (a very common solution on laptops).
3) What is HBM
A different type of memory is available for AMD video cards, sold as an exclusive product: HBM memories.
They differ from GDDR because the memory chips are not in the vicinity of the graphics processor (as seen in the previous image), but are present inside the GPU / CPU stacked in columns, thus sharing all the band, instructions and optimizations in terms of speed and energy savings.
This technology is at the forefront and allows you to store data at speeds that cannot be reached by GDDR, since they operate very close to the GPU (maximum data transfer speed).
Being an exclusive product, however, AMD had some difficulties in establishing itself on the market, although they are clearly better than GDDR: this is because the drivers and games must be optimized to take advantage of HBM otherwise you will not get any advantage from a performance point of view. Currently it is possible to find video cards with HBM and HBM 2, with the latter capable of competing with GDDR5x and GDDR6.
4) Conclusions
But in the end what is the best video memory "> If we don't know what type of video memory we use on our video card, we recommend downloading the free GPU-Z program .
To choose a new video card I refer you to reading our dedicated guide -> Best video cards for PC
