On Sat, May 2, 2015 at 10:20 AM, David Lanzendörfer david.lanzendoerfer@o2s.ch wrote:
Hi
What is the future of EOMA-68? Any EOMA-68 with a powerful hardware (like Tegra X1 or Intel Bay-Trail)?
Or the Loongson[1]: It is "free-er". An octa core costs 2500RMB and drains around 30W with nearly twice the computational power of an intel Sandy Bridge. So before you go for power-eaters++ like Intel or Tegra which even seems to enjoy the ride about proprietary GPU design, let's just use the dragon core.
the curreent Loongson is, as you say, 30W. EOMA68 (Type I) is a maximum of 5W, where the comfortable operating thermal limit is actually 3.5W - literally a tenth of the Loongson's power budget (and that's just the processor).
also, the Loongson processors are designed around a Northbridge-Southbridge architecture: ironically the best chip to use is the AMD CS5536 (the same IC that was used in the OLPC XO-1).
also, they require a 64-bit RAM interface (minimum) - i believe they might even require dual 64-bit-wide RAM interfaces. the power consumption from the memory alone is therefore going to be something of the order of 8 to 10 watts at 1333mhz or so.
so for a full Loongson system you would not be looking at a 30W budget, you would be looking at more like a 40 to 45W budget.
by contrast, for example with the A20 PCB we're looking at 32-bit wide 800mhz DDR3 RAM and that uses only around 350mW (0.35W), and the A20 itself only uses about 2.5 watts, flat-out.
the difference then, david, is absolutely enormous, making them totally unsuitable for EOMA68.
Loongson processors would however be *perfectly* suited to the EOMA-200 standard, which is designed *exactly* for this type of higher-powered processor.
however, as i am currently focussed on the easier-to-fund EOMA68, as a way to bootstrap up to profitability by which i can then focus on the *other* standards later, it would be foolish of me - unless you can find the funding and provide it to me - to change direction at this exact minute, especially when things are close to crowd-funding and take-off.
does that help clarify?
l.