30. Apr. 2025: Neue PPC-Hardware angekündigt: "Mirari" mit USB3, NVME, Onboard-FPGA (Update 3)
Dave 'Skateman' Koelman stellt im "Hardware"-Channel des Amigans
Discord-Servers ein neues, von Harald "Geennaam" Kanning entworfenes PPC-Motherboard vor.
Inzwischen hat sich auch Kanning selbst im Kommentarbereich von amiga-news.de
zu Wort gemeldet und uns eine ausführliche Beschreibung des
Projekts zukommen lassen:
Aktuell weist das "Mirari" getaufte Projekt die folgende Eigenschaften auf:
- Form Factor: micro-ATX compatible, 244x170mm (L x W)
- T10x2 (2-4 e5500 cores) up to 1.5GHz / T2081 (4 dual-threaded e6500 cores with Altivec 2.0) up to 1.8GHz
- DDR3L (1.35V) SODIMM with rank interleaving (T10x2 up to DDR1600; T2081 up to DDR2133)
- PCIe x16 slot with 4 lanes occupied (PCIe 2.0)
- PCIe x4 slot with one lane occupied (T10x2 PCIe 2.0; T2081 PCIe 3.0)
- PCIe x1 slot with one lane occupied (PCIe 2.0)
- 2x SATA 2.0 (T10x2 only, at 300Mbit/s)
- 2x NVMe slots (second slot mutually exclusive with second SATA port)
- 8 USB 2.0 ports (4 connected to the rear I/O; 4 connected to internal USB 2.0 headers)
- 4 USB 3.2 Gen1 ports (2 connected to the rear I/O; 2 connected to an internal USB 3.0 header)
- 10/100/1000 Mbit Ethernet
- 192kHz/24bit analog audio (mic, line-in, line-out to the rear I/O; mic, headphone to the HD audio connector)
- S/PDIF / Toslink digital audio out
- 9-pin RS232 to the rear I/O
- Micro SD card (push-in push-out) as boot source
- 24-pin ATX power connector
- 4-pin ATX CPU power connector
- CPU fan header with PWM
- Case fan header
- TRION FPGA
Background and Mission
The Mirari board is designed with the intention to provide the Amiga
community with low-cost PowerPC hardware. Therefore, the design is based on a
bare minimum with nice-to-haves based on what makes sense, but always with
the mission in mind. Due to the minor cost difference between a dual-core
T1022 and the quad-core T1042, we've decided on the T1042, resulting in a
low-cost board with mid-range specifications.
The T10x2 is based on the e5500 core, the same core found in the X5000.
Initial benchmarks confirm that the single-core performance difference is
just the clock difference, with a 1.4 GHz T1042 performing at 70% of the 2GHz
X5020. The design also accommodates the pin and footprint-compatible T2081,
allowing for a mid-cost board with high-end specifications. To ensure
compatibility, we had to make some compromises to the T10x2 design.
Memory Support
The T10x2 memory controller supports both 64-bit DDR3L and DDR4 at 800 MHz (DDR1600).
The T2081 memory controller supports both 64-bit DDR3L at 933MHz (DDR1866) and DDR3 at 1066MHz (DDR2133).
The common denominator is DDR3L, hence the choice for a 1.35V SODIMM slot.
If we had focused solely on the T1042, DDR4 would have been the better choice from an availability standpoint. However, since the clock speed is the same but latencies are larger for DDR4, the overall memory performance would have been lower.
For the T2081 we can increase the memory controller voltage to 1.5V which would enable the DDR2133 interface speed.
Although we have only one memory controller, initial Linux benchmarks show that the single and SMT memory performance is at least on par with the X5020.
Audio
For longevity reasons, we've decided to use an industrial-grade audio codec from TI (TLV320AIC3204). This codec is routed to three audio jacks at the rear (mic, line-in, line-out) and to an onboard HD audio connector. Additionally, there's a digital optical output (Toslink). The T1042 features an I2S interface for direct connection to external audio codecs, while the T208x does not. Therefore, we've implemented the I2S and S/PDIF controllers in the FPGA. This means there's no audio driver readily available for Linux. For OS4 and MorphOS, I have experience writing AHI drivers, so consider this covered.
Storage
The mainboard features two SATA ports and two NVMe slots. However, we had to make some tough choices again:
For the T1042 variant, there's always one SATA port and one NVMe slot available. The second SATA/NVMe is mutually exclusive, currently jumper-based but eventually u-boot configurable.
The T2081 does not have SATA interfaces. If you need SATA, it must be added with a PCIe card. However, keep in mind that SATA is being phased out, with modern PCs and laptops often using NVMe over SATA SSDs.
Tested Linux distributions are all booting and running from NVMe. I also have experience with NVMe drivers, so consider this covered for OS4 and MorphOS as well.
USB3: We based u-boot on the latest stable version available earlier this year, 2024.10. This has many benefits over using the 2014-2018 versions available in other PowerPC hardware. However, the developers behind u-boot changed the driver model around 2018, with a transition period ending in 2020. This means u-boot is a mixture of old drivers and drivers compliant with the new model. For USB on NXP SoC, there's a catch: NXP didn't rewrite their OHCI and EHCI drivers for the new model. Activating the XHCI driver for USB3 support causes conflicts. Fortunately, this is not an issue under Linux, so USB3 works correctly, but we have work to do for u-boot.
Prototypes
We have ordered 5 prototypes and managed to make them all work (100% yield). This was a great concern to me personally, as the layout requirements for the 780 balls FPGA stretched our supplier's capabilities to its limits. The boards run stably and have undergone hours of burn-in testing with Linux stress testing tools. One observation is that the CPUs run around 30°C idle and around 40°C under full load, which is good for overclocking potential. The core power supply has quite some headroom to support this. You can check out the Hyperion Entertainment X5000 Linux-only forum for posts from Skateman. Whenever he talks about his 4-core e5500, he is actually talking about this board.
Update: (30.04.2025, 23:20, cg)
Einige Anmerkungen des Hardware-Entwicklers aus einem nur für registrierte Discord-Nutzer zugänglichen Kanal (Official Commodore Amiga, #next-gen):
- "Das Board ist voll funktionsfähig. D.h. es laufen alle verfügbaren PPC-Linux-Distro's (einschließlich der neuesten Chimera). Dieses Board basiert aus Kostengründen auf dem T1042, hat also vier e5500-Cores. Aber das Board ist voll kompatibel mit dem 8 Threads e6500-basierten T2081. Andere hervorzuhebende Dinge sind 2x NVMe (Linux bootet und läuft von NVMe) und USB3.2 Gen1".
- "Das Ziel für die T1042-basierte Version ist es, das günstigste PPC-Mainboard auf dem Markt zu sein."
- "Ziel ist es, sowohl OS4 als auch MorphOS laufen zu lassen. Aber das liegt natürlich nicht an uns. Wir können nur so viel tun, wie wir kontrollieren können. Und das ist die Hardware einschließlich u-boot. Wenn diejenigen, die OS4 kontrollieren, letztendlich nicht kooperieren wollen, dann hatten wir wenigstens den Spaß. Und haben bewiesen, dass preiswerte PPC Hardware möglich ist."
- "Der T1042 unterstützt entweder 1,35V DDR3L oder DDR4. Der T2081 unterstützt entweder 1,5V DDR3 oder 1,35V DDR3L. Daher die Entscheidung für einen 1,35V-Sodimm. Für den T2081 könnte ich mich für 1,5V DDR3 entscheiden. Dann kann er auf DDR-2133 hochgetaktet werden."
Update 2: (01.05.2025, 13:15, cg):
Board-Designer Harald 'Geennaam' Kanning hat im Kommentarbereich von amiga-news.de eine ausführlichere Beschreibung des Projekts veröffentlicht.
Update 3: (01.05.2025, 15:39, cg):
Meldung komplett überarbeitet um sämtliche bisher verfügbaren Informationen besser strukturiert
zu präsentieren.
(cg)
