USB raisers are the devices that allow a miner to connect more GPUs to his/her mining rig. In other words, if you have a PCIe raiser, you won’t have to plug your GPU directly into your motherboard. You’ll need to plug your raiser into the motherboard, take a USB cable and connect the riser in your motherboard with your GPU.
The biggest advantage of the PCIe raisers is that they allow you increase the number of GPUs connected to your mining rig. A PCIe raiser itself will be plugged into 1 slot on your motherboard meanwhile there can be up to 16 slots on its end. In other words, such a raiser will allow you to connect up to 16 GPUs to your mining rig.
Due to the fact that one of the newest (and the best) motherboards introduced to the market have only 1 PCIe slot, there arises a need to use rather long USB cables in order to connect PCIe raiser to a motherboard. In this article, we’re going to talk about how far can GPUs be placed from a motherboard. Actually, everything depends on the length of the USB cables you’re going to use as well as the length of your power supply cables.
Can I get the USB cables of any length?
The thing is that the best PCIe raisers come with USB 3.0 cables. The length of the cables is standard. It amounts to 2-3 feet. It’s more than enough. Using such a cable you can place your GPUs rather far from your motherboard and your GPUs won’t be placed close to each other. There will be enough space in between them. Consequently, you can be sure that there will be air circulation and that your GPUs will cool down.
Some miners say that the PCIe raisers can be connected to the motherboard with the help of USB 3.0 cables that aren’t longer than 24 inches. (They assume so because the majority of PCIe raiser are sold with 24-inch cables) We’ve found out that there is nothing said about length limitations in the official USB 3.0 specifications. The only thing to check is if your cable meets electrical specifications. Let’s say you have an USB cable that has AWG 26 copper wires. So, you’ll be fine if you get raiser cables that are 4.3 feet (1.3 meters) long.
Remember that if you have very long cables, you may have some problems later on. The thing is that the cable that’s 20 feet long can easily get coiled up around something and, as a result, this cable can be damaged.
If you think that you need a long PCIe/USB riser cable, you’re free to get one. There is nothing wrong with it. However, you need to check that your cables are not coiled around each other. They should be straightened. there is one more thing to mention. We don’t recommend you buying flat cables. You’d better buy a high-quality USB cable (and make sure that you buy it from a well-known seller).