Technology & Positioning
The Acer Predator GM9000 is the company's first PCI-Express 5.0 consumer SSD. It uses the new Silicon Motion SM2508 controller, which is SMI's first Gen 5 controller for the consumer space. This review marks our first review of the SM2508, so it'll be interesting how it performs against the Gen 5 controllers from Phison and Samsung. The NAND flash chips used are Micron 232-layer 3D TLC—we've seen those on a lot of Phison E26 drives in the past. As expected from a drive with a flagship positioning, a DRAM cache is installed, too. We found 2 GB LPDDR4-3200 on the GM9000.

Synthetic Performance
The Predator GM9000 did well in our synthetic testing, performing better than the Corsair MP700 Pro (Phison E26), but slower than the Samsung 9100 Pro. While sequential writes and sequential mixed is near the top, sequential read at QD1 is a little bit slower than expected. Random IO is very good across the board. But what matters much more is real-life testing, because all controllers are optimized for typical synthetic reviewer workloads on a mostly empty drive. Our real-life testing is designed to run actual applications, not disk traces that compress time by assuming infinitely fast hardware and software. We're even running those tests with the drives filled to 85% capacity, not empty. This approach puts additional pressure on the various algorithms and the SLC cache, just like in real-life.

Real-Life Performance
In our real-life tests, the new SMI controller performed very well, achieving performance that's better than all the PCIe 4.0 drives on the market. It is able to match the Phison E26-based Corsair MP700 Pro and beats the Phison E31-based Kioxia Exceria Plus G4 by 2%. Only the Samsung 9100 Pro is a tiny bit faster, by 2%. Taking a look at individual benchmarks we can see that each controller wins some tests, and other controllers win other tests, depending on the load pattern and the controller's optimizations. Compared to older Gen 4 drives, the performance uplift is around 10%, but the best PCIe 4.0 drives with modern controllers are not much slower than the various Gen 5 offerings, unless of course you need those massive transfer speeds, which is quite rare.

SLC Cache / Sustained Performance
Acer has configured their drive with an SLC cache size of 381 GB (or 55% in SLC mode), which is enough to soak up nearly all bursts of write activity. Once the SLC cache is exhausted, transfer rates are roughly cut into half, but with 4 GB/s, they are still very high. After 1.3 TB, there's a second drop to 2 GB/s—still plenty. Filling the whole 2 TB capacity completed at 3.0 GB/s, which is a fantastic result that's better than almost all drives on the market. Samsung's new 9100 Pro only gets a meager 1.8 GB/s in this test. Only the fastest 14 GB/s Phison E26 drives can reach similar speeds as the GM9000.

Power Consumption / Heat
Thermals of Gen 5 drives have always been challenging, with all Phison E26 drives requiring an active fan-cooled solution, or a huge heatsink, or both. One of Silicon Motion's development focuses was to lower heat output, which requires better energy efficiency. Their SM2508 controller is fabricated using a 6 nanometer process at TSMC Taiwan. Our power consumption testing shows that efficiency is very good, reaching top spots for both read and write efficiency. The efficiency does not set new standards though, it's roughly similar to what Samsung offers with their Gen 5 controller, slightly behind the Phison E31, but considerably better than the Phison E26, which powers most of the high-end Gen 5 drives. While idle power usage is still a bit high, it's "close enough" to the various Gen 4 drives on the market. In a laptop I'd still opt for a Gen 4 SSD though, because some of these use only 1/20th the power of the GM9000 with ASPM active, which will help extend the battery life. With a maximum power draw of 8 W, the drive runs at around 2 W less than the Phison E26, a definite improvement, but not enough to stop thermal throttling. You still need a decent heatsink, the bare drive throttled fairly quickly with a stress-test workload. With lighter activity the GM9000 will run fine without heatsink and there will be some occasional throttling when heavily loaded, which is OK for many consumer scenarios. Power users should definitely install a cheap aftermarket heatsink, it will help a lot. Our thermal tests revealed that the sticker leads to considerable heat buildup and more throttling when a heatsink is installed on top of it. For optimal heat transfer, be sure to take it off when installing a heatsink.

What definitely doesn't help the thermal throttling situation is that the drive comes with VERY low thermal limits. It will start throttling at just 75°C (sensors) / 85°C (real surface temperature), which is one of the most conservative settings I've seen in a long time. Other drives use a higher thermal limit, which helps delay or avoid throttling. Silicon Motion, the controller manufacturer confirmed to us that throttling stages, thermal limits, etc. are fully customizable on their controller. This means that BIWIN (Acer's manufacturing partner), was very cautious with their settings and other SSDs based on SM2508 might have higher limits.

Pricing & Alternatives
While pricing of PCIe Gen 5 has been pretty high for years, the Acer Predator GM9000 is priced pretty competitively. Right now it's hard to find in Europe or the States, but in Asia it's readily available. Pricing for the 2 TB model is around $215 in Hong Kong, China and Taiwan. At this price point, it's a strong alternative to drives using the Phison E26 controller, which start at around $230. Samsung's 9100 Pro 2 TB is $300 right now—way too expensive. Strong Gen 5 competition comes from the various drives using the Phison E31 controller, these start at around $180, but offer lower overall performance, but better energy efficiency. Unless you need the super-high transfer rates, it's worth checking out Gen 4 offerings, too. We recently reviewed the WD Black SN7100, which is the fastest Gen 4 SSD we ever tested—$150. Other options are Samsung 990 Pro ($165), WD SN850X ($140) and of course the MaxioTech MAP1602 drives like the Lexar NM790 ($130).