you mean i can't 1x8Gb ram??
No. Your motherboard's chipset does not support larger than 4Gb modules
per slot.
Every motherboard, and
every device on the motherboard, is totally dependent on the specific chipset used on that specific model of motherboard.
Whether you must use an AMD processor or an Intel processor is determined by the chipset. And which AMD or Intel is also determined the chipset used. Same with RAM. This is why when buying a motherboard, you need to check the QVLs (qualified vendors lists) on the board's website to see what CPUs and RAM that board supports.
It is actually the chipset that determines if a motherboard is a budget, entry level board, or an expensive, high-end motherboard.
The maximum size RAM module (stick) your particular chipset supports is 4Gb per channel. Your motherboard has two slots (to support dual channel) so you can install up to 4Gb in each slot for a total of 8Gb (2 x 4Gb).
This is actually a good thing - at least in terms of performance. With 1 x 8, if your board supported 8Gb sticks, you would be running in single channel memory mode. But with 2 x 4 your motherboard will be running in dual-channel mode and while not double the performance, significant performance gains will be seen in many, if not most computing tasks.
I hope you didn't already pay for a 8Gb stick. If you already did, don't be tempted to try it. You may permanently damage the stick or motherboard, or both. Sorry.
You might check out the
Crucial Memory Advisor. You can plug in your details or let them scan your system (it is safe) and it will tell you what your board supports and offer guaranteed-to-work options. Most other RAM makers and many retail sites have have similar RAM "wizards".