acer aspire tc-895 upgrade list

You will need more of a cooling revamp in order to drop a K chip in. The TDP for your existing CPU is 65W, the K models are 125W, so you need to double your cooling. The Noctua cooler that the folks in the Gaming sections recommend will likely fit and provide enough extra cooling to allow an i7-10700K or 19-10900K. With the i7 or i9 installed you might be able to bump the memory speed up from 2666 to 2933. Note that the BIOS has no provisions for overclocking the CPU, so a lot of the K functionality isn't going to be available. If I were doing a CPU upgrade I'd go with an i7-10700 or i9-10900 instead, since no cooling changes are needed.

Any of the GTX 1660 variants require a 450W power supply, so you will have to upgrade your 300W. The issue there is the PSU you have is an ATX12VO supply, which provides only 12V to the motherboard (via a six pin and either eight pin or two four pin connectors). Those power supplies are really tough to find on the secondary market. Acer does ship some versions of the TC-885 with 500W supplies though, the part numbers are DC.5001H.001 and DC.5001B.009. You search on those numbers to find sources, the only difference between the two are the vendors Acer purchases from.

IIRC the Aspire TC-895-EB11 model comes with a 1TB HDD as the storage. You will get a much bigger boost in performance by adding a SSD into the M.2 slot (your system supports an NVMe x4 SSD which will be four times as fast as a SATA SSD and many more times than your existing drive). Purchase a brand name (I'd suggest a Samsung NVMe x4 3.0 1TB), put it in (you may have to buy the screw, check first to see if it was installed by the factory first) and clone the existing 1TB HDD to the new SSD then use the boot menu to choose to boot from the SSD. Once you are up and running and things are working correctly, use Disk Management to remove all partitions on the old HDD and create a new partition that uses the whole drive for data.

So, if it were me, I'd start with the SSD and do some performance tests within your environment. Next would be the PSU and GPU combo though you might look at the 2060/2070 and 3060/3070 options as well, they all work in a 500W environment. Next would be the memory upgrade, I would go with 32GB using two 16GB sticks. If you are going to upgrade the CPU to an i7 or i9 go with either 2933 or 3200, non-XMP. Acer used 3200 on those systems because they were easier to source than the 2933 for some reason. You may find the 3200 come in cheaper than the 2933 for that same reason. It will end up running at 2933 since that's what the chipset supports. Only last would I do a CPU/cooling upgrade and I'd stick with the Noctua for the cooling since so many people have good things to say about them in the Acer environment.

I think you will find that a SSD upgrade will give you by far the best performance boost. 1TB NVMe SSDs can be purchased for under $100 easily. You can put most any GPU in that runs off PCIe power only. If you have the 500W supply a GeForce RTX 3050 should work fine. It likely won't work with the 300W supply, but it's only power that causes that. The earlier RTX designs can also work, as long as they don't need too much power. The same thing applies for AMD GPUs, as long as they don't exceed the power budget they should work.

The PCIe x16 slot is 3.0 on a TC-895 model. PCIe 4.0 devices will work, but at the 3.0 speeds. Heck, PCIe 2.0 devices will also work, at 2.0 speeds. PCIe x16 slots themselves don't differentiate between cards, it's the OS that needs to deal with different cards differently.