Quickly to the right hardware equipment …
Layout, design and features
ASRock X870 Pro RS chipset
ASRock X870 Pro RS voltage regulators and heatsinks
ASRock X870 Pro RS expansion cards
ASRock X870 Pro RS memory modules
ASRock X870 Pro RS M.2 Slots
ASRock X870 Pro RS drive connectors
ASRock X870 Pro RS USB
ASRock X870 Pro RS Network / Wireless
ASRock X870 Pro RS Sound
ASRock X870 Pro RS thermal sensor/a>
ASRock X870 Pro RS RGB lighting
ASRock X870 Pro RS equipment and other features ASRock X870 Pro RS PC System
Now it’s time to take a closer look at the ASRock X870 Pro RS.
Layout, design and features …
The ASRock X870 Pro RS is based on an 8-layer PCB board and currently supports all AMD Ryzen CPUs of the 7000, 7000X and 7000X3D series as well as all APUs of the 8000 series and of course the recently released Zen 5 Ryzen processors of the 9000 series with the 1718-pin AM5 socket. The Zen 5 Ryzen 9000 X3D processors expected soon will of course also be supported with a BIOS update. 
In terms of power supply, ASRock naturally makes no compromises with the X870 Pro RS and has equipped it with 14+2+1 Premium 80A Smart Power Stages (SPS) and durable 1000µF capacitors. In addition, the X870 Pro RS has a Blazing M.2 slot for PCIe Gen5 x4 modules with up to 128 Gb/s connection. Another Hyper M.2 slot for PCIe Gen4 x4 modules with up to 64 Gb/s is located next to an additional Ultra M.2 slot for PCIe Gen3 4×4 with up to 32 GB/s below the 2nd PCIe x16 slot. For all M.2 slots, passive heat sinks are also pre-mounted and ASRock has also thought of a quick-release fastener for the upper M.2 heat sink and at least all M.2s can be mounted without tools, whereby the screws of the heat sink must first be loosened for the lower M.2 SSDs. With USB4 (40Gbps), which is mandatory with X870, the equipment package is rounded off perfectly. 
chipset …
At the heart of the ASRock X870 Pro RS AM5 motherboard is AMD’s Promontory 21 chipset, already known from the X670 and B650, which is available on the X870 Pro RS in a simple version and is therefore not a successor to the X670(E) but only to the B650E, which means that there are 4 PCIe lanes less available for interfaces. Below is an overview of how AMD has planned the connection of the interfaces (AMD X870E vs X870 vs X670E vs X670 vs B650E vs B650 vs A620). A different design by the motherboard manufacturer is possible.
| AMD AM5 Chipset Comparison | ||||||
| Chipset | PCIe total | PCIe Gen5 | USB 3.2 Gen1 | USB 3.2 Gen2 | USB 3.2 Gen2x2 | SATA |
| X870E | 44 | 24 | 2 | 12 | 2 | 8 |
| X670E | 44 | 24 | 2 | 12 | 2 | 8 |
| X670 | 44 | 8 | 2 | 12 | 2 | 8 |
| X870 | 36 | 24 | 1 | 6 | 1 | 4 |
| B850 | 36 | 4 | 1 | 6 | 1 | 4 |
| B650E | 36 | 24 | 1 | 6 | 1 | 4 |
| B650 | 36 | 0 | 1 | 6 | 1 | 4 |
| A620 | 32 | 0 | 2 | 2 | 0 | 4 |
As mentioned above, the X870 is the successor to the B650E. Why AMD has to create even more confusion here with this description than is already the case with the many variants remains unclear. However, with the table above, everyone should be able to find the chipset that best suits their needs.
New chipset variants in the mid-range and entry-level class are also already in preparation and should enable manufacturers to offer motherboards with the latest features at a lower price than the current high-end motherboards. With the descriptions B850 and B840, the names of the upcoming, cheaper chipsets are already known. Unfortunately, this does not make the chipset jungle for AM5 any clearer, but only more confusing.
Voltage regulators and heatsinks …
In the price category of the ASRock X870 Pro RS, a total of 17x 80A Smart Power Stages (SPS), 14 of which are intended solely for the power supply of the CPU, are already very stable. With this equipment, there is no need to worry about overclocking. 
To match this, ASRock placed generously dimensioned aluminum heat sinks on the voltage converters, which optimally dissipate the heat loss of the efficient Smart Power Stages. An active fan, as with the X870E Taichi, is not required here. 
Expansion cards …
The upper of the two PCIe x16 slots is a fully-fledged Gen 5 x16 slot. The lower x16 slot is only connected with PCIe 4.0 X4 and is also deactivated if the M.2_2 slot is used. It therefore makes no sense to install a second high-performance graphics card in the PCIe 2 slot. For the best possible stability and shielding against interference signals, the first PCIe slot is reinforced with stainless steel plates. Unfortunately, the new EZ release, which the ASRock X870E Taichi has received, is not yet used here. 
Memory modules …
The X870 Pro RS officially supports up to 256GB DDR5 RAM with its 4 DIMM slots. We can therefore assume that ASRock already has modules with 64GB capacity available for evaluation. Thanks to the high-quality 8-layer PCB, ASRock has already been able to verify RAM kits with 8000 MT/s using EXPO. EXPO is a protocol whose data is stored on RAM modules, which provides the motherboard with all the necessary information on how the RAM module must be addressed in order to function at the specified overclocking speed. Sometimes such high memory speeds could only be achieved by tedious trial and error of the settings and hours of verification with stress tests (see DDR5-8000 on B650E Taichi article). 
M.2 Slots …
Up to three M.2 SSDs can be used simultaneously on the X870Pro. The slot between the CPU and the upper PCIe slot is connected with 4 lanes of the 5th generation and the remaining two slots are connected once with 4 lanes of the 4th generation and once with 4 lanes of the 3rd generation. All common NVMe SSDs can be installed in the M.2_2 slot, in the M.2_1 and M.2_3 slots only the longer 2280. It is particularly pleasing that screws are no longer necessary, at least for fastening the M.2 SSDs, as all M.2 slots have been fitted with practical quick-release fasteners. 
Heat sinks have also been provided for all M.2 slots to protect high-performance SSDs from overheating. The Gen5 slot even has thermal pads on the underside and quick-release fasteners on the heat sinks. The lower heat sink is screwed on conventionally. Other ASRock motherboards in this price range, such as the ASRock Z890 Lightning WiFi tested by us, also offer tool-free heat sinks. 
Drive connectors …
A total of four angled SATA3 ports with 6 Gb/s are available for optical drives and hard disks/SSDs. RAID modes 0, 1 and 10 are supported on both the SATA ports and the M.2 ports. The necessary programs for RAID configuration and installation are available for download on the ASRock website. 
USB …
The X870 Pro RS also has no shortage of USB connections of various types and speeds. A total of 10 Type-A sockets and two USB4 Type-C connections are available on the rear I/O panel. The USB-C connections deliver maximum transfer rates of up to 40 Gb/s. Of the 10 Type-A sockets, 4 comply with the USB 3.2 Gen 2 (10Gbps) standard and 6 with the USB 2.0 standard (480Mbps). 
If that’s not enough, the number of usable USB ports can be significantly expanded. Two headers are available for a total of three USB 2.0 ports (480 Mb/s), one header for two USB 3.2 Gen 1 ports (5 Gb/s) and one header for a USB 3.2 Gen 2×2 header for front USB-C with 20 Gb/s.
Network / Wireless …
The familiar Realtek RTL8125B with a transfer rate of 2.5 gigabits is used as the LAN connection. WiFi is unfortunately not available, but it is prepared for it and offers an M.2 Key E slot. At least theoretically, as ASRock does not offer a suitable module with the appropriate antennas for the board. There are Intel M.2 Key E WiFi cards, but here you would have to use adhesive antennas that can be plugged into the WiFi module, but would have to be routed through the slot panel to the outside and possibly glued to the case. If you need WiFi, then we would recommend the ASRock X870 Pro RS WiFi with built-in WiFi card, which is available for around 20 euros extra. 
Sound …
The 7.1 sound is delivered via the Realtek ALC1220. The signal-to-noise ratio is a very good 120dB with an impedance of up to 600 ohms. However, as the ASRock X870 Pro RS only offers 2x 3.5 mm jacks on the I/O panel, the front connection must also be used for 5.1 and 7.1 sound playback. Although this works well, it unfortunately looks modest and you can’t connect analog headphones at the same time. Additional 3.5mm jack plugs on the I/O panel would make more sense here. At least there is an optical S/PDIF output on the I/O panel, which offers the best possible connection. 
Thermal sensor …
Here, too, a thermistor can be connected as a thermal sensor and its measured values can be used in the UEFI/BIOS for fan control, which we consider to be a useful addition, as the rapidly changing temperature of modern CPUs often results in wild fluctuations in the speed of the case fans, which on the one hand creates an unpleasant background noise and on the other hand is not really helpful. 
RGB lighting …
The ASRock X870 Pro RS also offers RGB lighting. This is located underneath the lower NVMe cover. A total of 6 RGB LEDs are installed here, which provide indirect aRGB lighting. In addition, the board has three 5V aRGB pin headers and a 12V RGB pin header. 
Equipment and other features …
The ASRock X870 Pro RS has numerous useful features, such as the ASRock A-Tuning Tool, ASRock Instant Flash, BIOS Flashback, NVMe Sanitization Tool, SSD Secure Erase Tool, Digi Power, ASRock Polychrome RGB and ASRock FAN-Tastic Tuning, Blazing OC Tuner, PD 3.0 Quickcharge, Lightning Gaming USB Ports, Auto Driver Installer. 2.5Gbit/s LAN offers a fast network connection. The new quick-release fasteners for M.2 SSDs and their coolers are also extremely practical, even if only the upper M.2 cooler benefits from this feature. Using USB4, external SSDs with a suitable controller can soon also be connected at more than PCIe 3.0×4 speed. The BIOS flashback function should also be emphasized, as the AM5 platform is also designed for future CPU generations, but their specification cannot yet be stored in the BIOS and will only be added later when the new CPUs are released. The necessary BIOS update can then be carried out using a USB stick without a CPU being present.
Test System …
For the test of the ASRock X870 Pro RS we use an AMD Ryzen 7 7700X CPU and 2x 16GB DDR5-6000MT/s CL36 from Crucial.
For cooling, we rely on the Sapphire Nitro+ S360-A AiO cooler from Sapphire, which achieved excellent results in our test. Thanks to the unchanged cooler mounting points, AM4 coolers can in most cases continue to be used on AM5 systems without any problems. For the thermal paste, we rely on a product from Arctic, namely the MX-4 paste with high thermal conductivity (see thermal paste comparison test). It does not dry out even after a long period of operation and is not electrically conductive, which is an advantage with the new AM5 CPUs because it has exposed SMD components on the top. 
When installing the Samsung 960Pro M.2 SSD, we once again wondered why this type of quick-release fastener has not always been implemented on motherboards. Installing the SSD is much easier and you don’t have to worry about losing the tiny fastening screw in the PC where it could cause a short circuit. 
The necessary power is supplied by a proven 650W XG Plus 650 Platinum power supply from Cooler Master, which provides more than enough power reserves for the 105W CPU with integrated graphics unit and the Asus TUF Gaming OC RTX graphics card used.
ASRock X870 Pro RS BIOS and overclocking …