How to upgrade the hardware chassis of Lianjiayue brand old host? The configuration is a little small as follows.

The motherboard is H6 1 chipset, so it is enough to replace the CPU with i5-3470 or i5-3570. Replace with CPU radiator with three or four copper heat pipes. Because your chassis is half-height and small, you can only use the push-down radiator (I recommend the one below, overclocking three Ladybug V6, which is used in my old half-height chassis, and the heat dissipation effect is good).

In terms of memory, it is suggested to unplug the original memory and replace it with two single 4G DDR3 1600 double-sided granular memories to form 8G.

I saw in your comments that GTX780 was not lit. One of the reasons is that this graphics card needs independent power supply. Of course, if you don't plug in the power cord of the graphics card, it won't light up. Another reason is that the power consumption of GTX780 is quite high. The official suggestion is that only 5 or 600 W rated power supply can be used. However, the power supply of this small office cabinet is generally rated at 2 or 300W at most, so even if the power cord of the graphics card is plugged in. The only way is to change the power supply, but since you have a half-height chassis, the standard size power supply can't be put down. You can only buy a TFX-sized power supply (as shown below), and directly search for TFX on Taobao. At present, the highest rated power I can find is 450W W. The internet said that 450 W could move GTX780, but it said it couldn't move, so I had to buy the test myself.