The Bottom Line
- + Performance
- + AMD Ryzen AI
- + 2.5Gbe Ethernet
- + Wi-Fi 6E
- + USB4
- - Limited I/O
- - HDMI 1.4a
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Introduction, Specifications, and Pricing
ASRock is one of a few vendors currently going all in designing and building AMD Ryzen 7000 series mobile Mini PCs. We noted this months back when we reviewed the 4x4BOX 7735U. The 7735U was an impressive Mini PC with solid enough performance to be a small form factor gaming machine with its Ryzen 7 CPU and Radeon 680M graphics. The 7840U looks to one up that model with a slightly better CPU in the Ryzen 7 7840U and Radeon 780M Graphics, along with AMD's new Ryzen AI technology, which is enabled on this model.
Our review model was a barebones unit. At the core of it, we have a Ryzen 7 7840U processor, an eight-core / sixteen-thread mobile part from AMD offering boost speeds up to 5.1GHz with a peak TDP of 28W. This machine supports two DDR5 modules via internal SO-DIMM slots. We chose to pair it with a set of TCreate sticks from TeamGroup for this review. Storage includes support for one PCIe Gen 4 NVMe solution along with a single 2.5" SATA drive.
Connectivity includes two USB4 ports supporting DP 1.4 for 4K60 compatibility. We also note a single USB 3.2 Gen 2 on the front panel and two USB 2.0 on the rear I/O. Networking includes dual LAN, one being a 2.5Gbe and the other 1Gbe, both from Realtek. Wi-Fi 6E is available as well; Realtek supplies the chipset here, too.
The MSRP of the ASRock 4x4BOX 7840U comes in at $579 as a barebones unit.
Overview and BIOS
The ASRock 4x4BOX 7840U was delivered in their standard industrial packaging, as seen above.
This unit includes the power brick rated at 19v 6.3A, a VESA mount, and additional hardware.
The front of the machine houses two USB4 ports alongside a single USB 3.2 Gen 2 and 3.5mm audio jack.
The top of the unit carries the power button.
The rear I/O includes power input, dual USB 2.0, and HDMI ports. On the far right, we find the dual LAN and Kensington lock.
Internally, we have two DDR5 SO-DIMM slots at the bottom, with the 2280 NVMe slot above and the M.2 Wi-Fi slot living underneath. The lid of the machine houses the tray for any 2.5" drive.
The BIOS on this machine is the basic system, and the main menu gives hardware information. The advances tab expands to provide support for the CPU, chipset, and storage. Further down, you can enable DASH support and update the BIOS.
The hardware monitor keeps track of the device's temperatures and voltages, along with a switch for enabling full fan speed.
Cinebench is a long-standing render benchmark that has been heavily relied upon by both Intel and AMD to highlight their newest platforms during unveils. The benchmark has two tests: a single-core workload utilizing one thread or 1T. There is also a multi-threaded test that uses all threads or nT of a tested CPU.
Single core performance for the 7840U landed middle of the pack in our charts at 1687; this was a bit better than the 7735U tested earlier in the year.
Multi-thread was the best we have seen from an AMD-powered Mini PC, with the 7840U scoring 13070.
CrossMark™ is an easy-to-run native cross-platform benchmark that measures the overall system performance and system responsiveness using models of real-world applications. CrossMark™ supports devices running Windows, iOS, and macOS platforms.
Crossmark landed the 4x4BOX fifth in our charts, quite a bit better than the 7735U. The score was 1700 even.
Memory performance reached 62K read, 86K write, and 68K copy. Latency finished up at 94ns.
Geekbench CPU gave us a single core score of 2537, about 300 points shy of the 13900H in the Mini IT13 recently reviewed. Multi-core pushed 11670, which was a good amount better than the 7735U.
GPU performance was the best we have seen from a Mini PC, the 7840U grabbing 29934 in OpenCL and 33083 in Vulkan.
UL Benchmarks and Final Thoughts
CPU Profile finished third in the one and two-thread workloads, the quickest AMD platform we have tested.
With four through sixteen threads, the 7840U again maintains third in our charts.
Time Spy was the best yet, as expected. The 780M, a rather decent entry-level GPU, scored 2935 overall and 8821 for the GPU.
3DMark Storage ranked third in our charts, with the 4x4BOX scoring 2662.
ASRock's 4X4BOX 7840U comes away from testing a touch better than the 7735U we tested earlier in the year. Physically, the two units are very similar, sharing the same design, including the chassis and much of the internal layout. This continues into the connectivity, which includes dual USB 2.0 on the rear of the unit along with dual LAN, one port using 1Gbe and the other 2.5Gbe.
This unit, too, supports dual HDMI, though we noted the rear ports only support the 1.4b standard, so it is a limitation for those wanting multiple 4K displays. That said, you can deploy DisplayPort over the USB4 ports found on the front for full 4K60 compatibility. USB4 also gives the ability to use eGPU for anyone considering using this as a gaming machine. Also in the wheelhouse of the 7840U is the Ryzen AI capability, which needs to be enabled by the vendor; ASRock has done that with the 4X4BOX.
Looking at performance, the 7840U was the quickest AMD machine we have tested and the best overall Mini PC. If your goal is gaming, this machine can provide solid entry-level performance right out of the box. Intel 13th Gen still reigns supreme for CPU-leaning workloads, but looking at our charts, the 7840U isn't far behind, with single-thread performance in both Cinebench and 3DMark offering a rather large uptick over last gens 6900HX.
Looking at full system performance, the 4X4BOX provided a near 100-point uptick over the 6900HX, going from 1606 points to 1700 points. Storage performance for this machine was quite good - we deployed our Sabrent Rocket Plus G for this review, and the 4X4BOX landed third in our charts, even beating out the NUC 13 Pro.
Pricing for the 4X4BOX-7840U comes in at $579.99, the same pricing we had on the 4X4BOX-7735U earlier in the year. Comparing the two units, both share the same connectivity options, chassis, and internal layout, but the 7840U has the benefit of Ryzen AI and the newer Radeon 780M graphics.