ASUS Prime Z790-P WIFI upgrade guide: RAM, SSD and CPU

Lifecycle and support

Standard support ended on October 2025 (estimate).

Dates not listed haven't been published by the manufacturer or a reliable third party.

RAM

What fits: four full-size desktop DIMM slots, dual-channel, DDR5 only. The modules must be non-ECC and unbuffered. A DDR5 stick is notched differently from DDR4 and earlier generations, so an older module will not physically fit. (DDR5's on-die ECC is not the same as ECC memory support; this board has none.)

Limits: up to 192 GB in total, which assumes four 48 GB modules. ASUS's manual lists 8 GB, 16 GB and 32 GB sticks because it was written before 48 GB modules existed, so don't be alarmed if the booklet seems to cap out lower. Top speed is DDR5-7200+ (OC), and that is a best case with a pair of modules and an XMP profile. Real-world speed depends on your CPU and how many modules and ranks you install, so expect less with four sticks or dual-rank memory. The board can be unable to reach its maximum rated speed because of platform constraints.

What to watch out for: stick to matched modules with the same capacity and timings — ideally the same kit. If the two channels differ in size, the extra capacity runs single-channel rather than in dual-channel mode. If you fill the slots or overclock, consider better airflow around the memory.

Buying tips: buy a matched kit in the capacity you want rather than adding sticks later. Check ASUS's memory support list (QVL) for this board before buying if you plan to run high XMP speeds. If you own the D4 version, buy DDR4 instead — it takes up to 128 GB.

Buying tips

• Matched kit, same size and timings
• Check ASUS's memory QVL for the board
• DDR5 for this board, DDR4 only for the D4 version

Storage

What fits: three M.2 slots (Key M) and four SATA 6 Gb/s ports. The M.2 slots take 2242, 2260, 2280 and, in two of them, 22110 lengths. The third M.2 slot also accepts SATA M.2 drives; the other two are NVMe only. Standard 2.5-inch and 3.5-inch SATA drives work too, though whether they physically fit is down to your case's drive bays.

Limits: all three M.2 slots are PCIe 4.0 x4, so a Gen5 SSD will run at Gen4 speed — there is no point paying for PCIe 5.0 storage here. Long 22110 drives fit only in the first and third M.2 slots; the middle one stops at 2280. Intel RST supports RAID 0/1/5/10.

What to watch out for: the manual documents SATA M.2 support in the third M.2 slot but does not confirm whether using it disables one of the SATA ports. If you want all four SATA ports plus a SATA M.2 drive, check the board's block diagram in the manual first, or ask ASUS support.

Buying tips: any NVMe PCIe 4.0 drive is a good match. Put your fastest drive in the first M.2 slot. Pick 2280-length drives unless you specifically want a 22110 model — that size is the most widely stocked.

Buying tips

• PCIe 4.0 NVMe is the sweet spot
• 22110 drives: use M.2_1 or M.2_3 only
• Check SATA port sharing before using a SATA M.2 drive

CPU

What fits: one socketed Intel LGA1700 socket, supporting 12th, 13th and 14th Gen Intel Core processors plus Pentium Gold and Celeron. Nothing is soldered, so the processor can be replaced.

Limits: ASUS publishes no official TDP ceiling for this board. It is a budget design with a 12+1-phase VRM, so the power delivery is the practical limit: sustained all-core loads on i9-class chips are the main thermal and power consideration. Turbo Boost is supported, with the newer Turbo Boost 3.0 depending on which CPU you install.

What to watch out for: the original manuals list only 12th and 13th Gen processors, while the current spec pages add 14th Gen — so a 14th Gen chip likely needs an up-to-date BIOS. ASUS's CPU support list is the authority here: check it before you buy, and update the BIOS first if you are moving to a newer generation.

Buying tips

• Check ASUS's CPU support list first
• Update the BIOS before fitting a 14th Gen CPU
• Consider the board's power delivery before choosing an i9

How to upgrade

Before you start

• Back up anything you care about, especially before storage or CPU work.
• Shut down, switch off at the PSU and unplug the power cable.
• Ground yourself to avoid static damage — touch the case metal or use a strap.
• Open the case and install the part (RAM clicks into its slot, M.2 drives mount at the slot's standoffs, the CPU drops into the LGA1700 socket). Follow the owner's manual for the exact disassembly steps and any screws or latches.
• Close the case, reconnect power and start up.
• Enter the BIOS/firmware to confirm the new RAM, drive or CPU is detected, and enable an XMP memory profile if you bought faster modules.

Steps

1. General install routine
   The same safe routine works for all three upgrades. For RAM, line up the notch on the module with the slot key before pressing it down. For storage, note that 22110 drives fit only in two of the three M.2 slots. For a CPU, update the BIOS first if you are installing a 14th Gen processor on a board with older firmware. The owner's manual covers the exact steps for your case and board revision.

Good to know

• The manual and the spec sheet disagree on maximum RAM: the booklet lists modules up to 32 GB while the current spec sheet states 192 GB total. ASUS has not confirmed whether a SATA M.2 drive in the third M.2 slot disables a SATA port.
• Memory speed depends on the CPU and on how many modules you install, so the headline DDR5-7200+ (OC) figure is a best case, not a guarantee.

Frequently asked questions

How much RAM can the ASUS Prime Z790-P WIFI take?

Up to 192 GB, using four 48 GB DDR5 modules. ASUS's manual only lists 8 GB, 16 GB and 32 GB sticks because it predates 48 GB modules; the current spec sheet confirms 192 GB.

Can I put DDR4 memory in the Prime Z790-P WIFI?

No. This board is DDR5 only, and the slots are keyed so DDR4 and older modules will not fit. The D4 sibling board is the DDR4 version, so buy memory to match the board you own.

Does it support PCIe 5.0 SSDs?

There is no PCIe 5.0 M.2 slot. All three M.2 slots are PCIe 4.0 x4, so a Gen5 drive will work but run at Gen4 speed.

Do I need a BIOS update for a 14th Gen CPU?

Probably. The original manuals list only 12th and 13th Gen processors, while the current spec pages add 14th Gen. Update the BIOS to the latest version before fitting the new CPU.

Does it support ECC memory?

No. Both the DDR5 and D4 versions require non-ECC, unbuffered modules. The on-die ECC inside DDR5 sticks is a different feature and is not server-style ECC support.

Which CPUs fit the Prime Z790-P WIFI?

Intel LGA1700 processors: 12th, 13th and 14th Gen Core, plus Pentium Gold and Celeron. Verify the exact chip on ASUS's CPU support list, and keep the board's power delivery in mind for i9-class parts.

Official documents and references

• ASUS Prime Z790-P WIFI — official specifications
  Memory, storage and CPU support details for the DDR5 board.
• PDF ASUS Prime Z790-P WIFI — user manual (PDF)
  Slot layout, module keying and installation details.