for RAM always consult the manufacturer documentation... it's free... it's easy... no probably needs
google "P8Z77-V motherboard" results in
https://www.asus.com/us/SupportOnly/P8Z77V/HelpDesk_Knowledge/
choose memory/device support and look for RAM QVL (qualified vendor list) as well as the basic user's manual.
https://dlcdnets.asus.com/pub/ASUS/mb/LGA1155/P8Z77-V/E7074_P8Z77-V.pdf
page 2-6 You may install 1GB, 2GB, 4GB and 8GB unbuffered and non-ECC DDR3 DIMMs into the DIMM sockets. There are 4 sockets, so at most you can have 32gb total RAM using 4x8gb DDR3 DIMMs.
the RAM QVL will list approved memory speeds and timings, such as F3-19200CL10Q-32GBZHD
The QVL shows DDR3 1600
up to DDR3 2600
. If you buy DDR3 greater than 2600, they will typically down clock and still work to meet the motherboard which is limited to DDR3 2600 but you do take your chances in doing so. With DDR3 being obsolete kinda you may only find cheaper DDR3-3200 for example, which is ok, but ideally choose something comparable to the RAM QVL. You do not require the GSkill
or Corsair
make, or only those makes listed on the QVL, while they are probably the better/best out there the no-name brands on amazon or elsewhere will work. Just go by DDR3 between 1600 and 2600 and a kit of 4x8gb dimms. There is an SSD QVL from ASUS you can also reference as well, although any sata ssd on amazon will work. consult the documentation and email ASUS for confirmation before buying a pcie nvme type storage device to hold a bootable operating system.