TOS struggles with 4k monitors. Try it with just one 4k monitor and see how it performs. This will simulate the number of pixels of having four 1080p monitors.
I don't have 4k monitors but I have tried a few before returning them. I noticed TOS would lag some when resizing chart windows on the 4k monitor if I was using integrated graphics. It wasn't as bad with a dedicated gpu. That was with just one 4k monitor attached and no other monitors. I suspect you are asking too much of your graphics card with four 4k monitors. You have several options. Swap out the 4k monitors for 1080p, 1200p or 1440p monitors. Another option is add a 2nd gpu to your computer. Then each gpu only has to run 2 monitors. Or you could switch to another trading platform, preferably one that doesn't use java.
Most code written for trading platforms is not written by top programmers or they just have different priorities. Most don't care about displaying hundreds of charts, all updating in real-time. I have written real-time graphics in C++ and Java for different companies. Done properly, you don't need crazy graphics cards, just enough to connect to 4 4k monitors. There is very little difference between C++ and Java (and I assume C#) in terms of speed. Several exchanges run on Java as do many funds. It is very fast. For true HFT C is used to modify the Linux/Unix kernel to run the data pipeline as fast as possible. If you are not doing that, and you don't already know C++, Java, or C# would be a good choice IMO. We are up to Java 17 now. It is completely modern. There are issues with any language. Bad points with Java: It uses more memory, mostly because of the JIT compiler. It is slow to start, mostly because of the JIT. The JIT takes a little time to warm up. Of course, the Just-In-Time compiler is also why it is so fast. Unfortunately, I don't know what platform would meet the requirements of the OP. I wrote my own and I don't use any graphics. If the OP really wants to do HFT then he/she doesn't need graphics either. So, what are there their end goals?
We (Medved Trader) made efficiency a priority from the start. The application is fully multithreaded, all the charts/indicators/scans/alerts are state machines, and displaying 100 charts is no problem. We are also very mindful of memory efficiency. But it does complicate things when you write the code We are old school programmers, brought up in the times of tight CPU/memory restrictions, most modern programmers are spoiled by the power of modern computers and efficiency is usually not a big priority. That said, few users display 100 charts at the same time.
Agreed. I don't know what the OP is thinking, but if you are basing your trading decisions on 100 charts in real-time, you are not in the realm of HFT. A platform that can handle 100+ charts and has tools (or allows you to write code) to enter and exit positions quickly may be what is needed. BTW I also use state machines all over the place.
Is this about MT? Yes - first month is free. In fact it is free after first month as well, with some limitations.