I'll call this a "semi-review" because, well, the system is a work in progress and getting the most from it will take time. Relatively little is optimized for PowerPC these days, and even less still for little-endian PowerPC or POWER9 in particular. If you want performance benchmarks, you can read Phoronix's performance tests which are substantially more thorough than anything I could gin up. This is about my experiences with the unit now that I've been using it most of today with my early firmware issues now largely corrected.
For what's in it, see my unboxing photographs from a few days ago. This system is best described as a middle-road configuration now that the 22-core chips are becoming available. It contains two four-core Sforza POWER9 processors on a 14nm process at 3.2/3.8GHz with 512K of L2 and 10MB of L3 per core; there is a discrepancy with the wiki which says 3.1/3.7 but you can read Raptor's spec sheet. SMT is available. By having both processors installed, all of the PCIe slots in this machine are unlocked (this was a deliberate design decision for efficiency, not to make you buy hardware you didn't need). All of the options in this unit are factory-installed: 32GB of ECC DDR4 RAM (maximum 2TB), an AMD Radeon Pro WX 7100 workstation video card (roughly a hopped-up RX 480), a Samsung 960 EVO 500GB NVMe SSD on a PCIe card and a Microsemi PM8068 SAS 3.0 controller. The machine comes stock in a Supermicro CSE-747 EATX case with two redundant 1400W power supplies, a SATA controller, onboard VGA, onboard USB 3.0, onboard 2xGigE network ports (Broadcom BCM95719), onboard RS-232 serial and an LG Blu-ray drive. A recovery disc with the factory firmware and manual is included. Sticker price was approximately US$7200.
No operating system is installed except for Petitboot (more in a moment). This machine should eventually run anything that supports it (of course it will run NetBSD, at least someday), but your sole option right now is Linux, and bleeding edge Linux at that: Raptor's excellent tech support team tells me that kernel 4.13 is minimally required and 4.16 is strongly recommended. This greatly limits your choices out of the box especially if you don't already have another Linux system to support bringing this one up. I didn't, so I selected Fedora 28, which supports ppc64le and has kernel 4.16. As of this writing, the final release of 28 has just hit the streets, so that's very timely. Officially Fedora only supports the Server flavour on ppc64le, but we can convert that to a Workstation version after it's installed.
The system boot sequence has several stages. You can read about them in a bit more detail on the RCS Wiki, but the breakdown is not unlike that of a modern POWER server, since this is mostly a modified OpenPOWER design. Immediately when power is applied, the system boots the "BMC" Baseboard Management Controller, which runs on an ARM6L service processor. This sits idle when the main processors are powered down. When the power button is pressed, the BMC starts the Initial Program Load (IPL) process on the main POWER9 CPUs from PNOR flash. Through a complex six-stage process the IPL terminates with loading Petitboot, a simple loader inside a tiny Linux environment called Skiroot. Since Petitboot is running in a tiny Linux, its presence simplifies driver support for the main operating system by handling platform functionality directly via the OpenPOWER Abstraction Layer. Petitboot, in turn, kexec()s into the OS kernel and, at least in theory, away you go.
Initially the fans came on at IPL at a terrific volume such that my wife and I could not reliably hold a conversation in the same room (no exaggeration). In addition, while I could get Petitboot to display on the Radeon card, the operating system wouldn't appear -- I had to use the onboard VGA to boot, which was inconvenient for my KVM and meant my expensive workstation card was doing nothing. Raptor's tech guys listened to my frustrated pleas and notified me immediately when the most current firmware was available. When I loaded this firmware on the system, it worked beautifully for about 10 or 15 minutes and then started freaking out, failing to see the NVMe, kernel panicking on the Fedora disc that it used to boot from, etc. Raptor got me another command to blank the GUARD partition on the PNOR flash to try to reset it, and the machine started working! In fact, I've been using it since about 11am today non-stop, so I consider that to be an excellent burn-in period. Oddly, I can't get Petitboot to appear on the WX 7100 output now, but the OS does, so it's not a big deal (I can just switch to VGA if I need to get into the bootloader until that gets fixed). This all happened literally within the space of a few days. The fans rev up and down periodically, which can be a bit disconcerting next to my usually quiet Quad G5, but they are no longer anywhere near as shrill or constant and I only notice them if the room is warm.
Power usage, incredibly, is quite modest for a machine of this specification. When you connect the power, the BMC sits idle at around 13W with a very quiet fan running. Starting IPL, the fans do still come on full blast at least initially and power usage jumps immediately to 143W. This climbs slowly to 212W by the time you hear the beep from the system indicating Petitboot has started. Petitboot then starts Fedora and once Fedora has booted and we are at the login screen, power usage drops back to around 150W and the fans automatically throttle down. I got out my infrared thermometer and checked the heat coming out the back, and found it was a very reasonable 91 to 99 degrees Fahrenheit. (The cat likes the G5 better for heat.) Most tasks barely moved the needle after that. I did some installations with dnf and the power usage barely rose to 160W. Compiling OpenSSL got it up to 177W. This is all less than the Quad G5 next to it, which right now is reading 238W on the UPS while sitting largely idle in Reduced power mode. On the other hand, I'm not using the video card very heavily, so this output could jump quite a bit once I get some games running on it. There are also no drives connected to the RAID yet, just the NVMe SSD.
You can expect an upgrade path with this hardware as well. Besides accepting any hardware accessories that are compatible with Linux (though see below), Raptor is planning to make additional processor options available if you have the thermal headspace and the power capacity, even this 22 core monster. Unlike the Quad G5, this system shouldn't be a dead end.
So that's the hardware. Let's talk about the software. This isn't under Raptor's control necessarily, but it will play into your decision-making process should you make an investment in one.
There are really two kinds of customers for the Talos II: people like me who dislike x86 on technical grounds and Intel's continued hegemony and wish to support alternative architectures of comparable performance, and people who are paranoid and want a system that is far less of an opaque closed system that they can audit and trust than what passes for commodity hardware these days. There is naturally some overlap between these two groups. The second group will probably put up with a little more inconvenience for the sake of ultimate privacy than the first group, which is more concerned about functionality. You should think long and hard about where you fall here, because it will affect how you perceive the system.
The major selling point to the second group is that the firmware is fully open-source and auditable even down to the FPGA level. Schematics are included! You can download and build your own FPGA flash image, your own BMC flash image and your own PNOR flash image. In fact, you are expected to, though Raptor provides pre-built versions assuming you trust them and their warrant canary. As long as you don't brick the BMC -- though this is doable if you are incautious -- you can play around with Petitboot and Skiboot pretty much at will and just reflash if you screw it up. Programming the FPGA means you'll need your own SPI programmer, but there's a JTAG port on the board and you can plug right in. Note that this scheme isn't perfect because you still have to trust a certain amount of the other firmware in the system, mostly in the various peripheral devices, but it's clearly better than what you'd get from any other system and it's a strong start towards reclaiming control of our own machines. Although I haven't tried writing my own custom firmware yet, it's very easy to build and flash the prefab releases, and the process is well documented. To upgrade to the current firmware from the v1.02 my machine came with did not require flashing the FPGA, so I could do it all from my G5 by talking to the BMC over SSH.
For the first group, however, that alone won't be satisfactory, because we actually want to use this thing as a computer. Frankly, my plan is to make this the Power Mac G5 successor that never was. It certainly has the specs for it. Unfortunately, this part is the bit that's not yet complete. I haven't tried other operating systems other than Fedora 28 yet, but I can't imagine the experience is much different, so take these observations at face value.
Because Fedora doesn't offer a direct download for Workstation on little-endian 64-bit PowerPC, you have to install Server first, and then switch to the Workstation environment. This will download the remaining missing pieces; I selected the default Workstation environment, which is based on GNOME. Hopefully future distros supporting this machine will do better than this process. While in use the system is perfectly responsive but seems slower than it ought to be at times, particularly compared to the Quad G5, though this is probably an unfair comparison. The G5 is running Mac OS X 10.4.11, an OS written by its manufacturer and highly optimized for it. The Talos II has to contend with an OS for which it is not the primary target, nor one that is particularly tuned for any PowerPC system.
There are various glitches and many things don't work yet. The first and most important deficiency is that I still can't get amdgpu working in Xorg, so I'm using framebuffer support (fbdev). This means the video card is still going largely underutilized. I expect this to improve as Polaris support improves, but it's not there yet. For this reason I haven't even bothered trying to load any games on it so far.
Multimedia is also limited because I don't have a sound device. lspci alleges the WX 7100 has some sort of audio support, but the open source drivers don't currently support it. I'll likely solve this problem with some sort of USB audio out in the meantime, but that's suboptimal. I haven't tried playing DVD or BD movies on it yet either for that reason.
Fedora didn't like the GBU-421 Bluetooth USB dongle I use with the G5. The G5 needed no drivers and it just "works," but GNOME doesn't see it. I had to transfer the picture above from my phone to the G5, and then to the Talos.
A few of the included applications either misbehave or don't work at all, though most fortunately do. The GNOME Software application kept complaining about incorrect checksums, but dnf was fine from the command line. Firefox 59 crashes with a segmentation fault on start-up (like I say, I guess I've got a project now). GNOME Web (formerly Epiphany) does work, but it's WebKit and I don't like that, and it too is not very well optimized. It does pretty well, though, considering; it got 2455ms on SunSpider, which would seem like a dismal number given that the Quad G5 managed 2255ms in TenFourFox, except that TenFourFox has a JIT and GNOME Web here is running interpreted, and TenFourFox is compiled with CPU optimizations specifically for the G5 while GNOME Web and the system WebKit have no specific optimizations. I'm also unhappy there's no Gopher support. On the other hand, you would expect YouTube videos to be a slideshow (no JIT, little or no SIMD), and yet they play at a surprisingly good framerate, just muted. This post is being written in GNOME Web.
However, much of the rest of it does work. Since I intend this to be a successor to my G5, I spent most of the afternoon making GNOME more Mac-like. Using Fondu, I copied the Lucida Grande font from Tiger and converted it back to TTF (to compile Fondu on the Talos, configure it with ./configure x86_64-unknown-linux-gnu, since it doesn't know what the heck a little-endian PowerPC is) and installed it. I then installed the GNOME Tweaks tool with dnf and a Mac GNOME theme and Dock extension. (Some other ideas are on this how-to.) I switched the system font to Lucida Grande in the Tweaks tool, disabled hinting entirely and left it with greyscale antialiasing, turned on User shell themes in Tweaks, and wrote a minimal shell theme to make the top bar more like a Mac menu bar. It's not perfect, but it's a good start. I'll provide it later if people are interested.
To get my Mac shortcut keys back, I installed AutoKey (autokey-gtk), and started making equivalents. A few clashed with GNOME, which I changed from Settings, and I altered a couple others in Terminal, but they mostly just worked with everything else including GNOME Web.
Let's bottom line it. As far as value for money, the machine is well-assembled, solidly built (if in an unexciting enclosure) and consists of quality components. I think the above paragraphs also demonstrate that the level of support from Raptor is absolutely commensurate with what you would expect for a $7000+ computer. Frankly, it's one of the best technical support experiences I've ever had with any system. Part of that is undoubtedly the low production numbers and highly technical engineering audience, but I have never felt like the machine was an unrecoverable doorstop even when it wasn't suitable for use yet.
Software, however, is still a work in progress. You should not expect a 100% functional system at the end and you don't even get a functional system out of the box. Not only will you have to install an OS and go through that process, you're also pretty much guaranteed that something won't work when that part is done. And even when everything you need actually is working, nothing is optimized for it; many things will run abnormally slowly until "someone" (tm) does this work. It's been a long time since PowerPC was a common desktop platform, so many of the optimizations Intel systems take for granted just don't exist, and some desktop apps aren't even tested.
But all of these things are correctable. The hardware is solid. The firmware rudiments are coming together; look at how quickly this machine evolved in just a few short days. Software is likely to be an easier nut to crack on the little-endian Talos than on previous big-endian PowerPC systems, too. Assuming there aren't dependencies on complex assembly code blocks, more code is likely to "just" work with fewer or no modifications because the assumptions made for mainstream x86 will now largely apply here as well. This depresses me personally since I think in big-endian, and have used big-endian systems for decades, but that's the way things are now.
I'm looking forward to this system becoming my daily driver and it might even happen in just a few months. I need to get Firefox working, and I need to get QEMU optimized to run my old Power Mac software. That's all doable. Once the video card and sound options are fixed, I can even start using it for multimedia and games, and the G5 can then become a well-cherished part of my collection.
This is a fully free system you can live with. This is a fully free system that can kick ass. The promise was kept and the dream is real. It's time to get busy.