Talk:Sun4d

The Architecture section should be mostly about the XDBUS. I'm having a hard time finding info on that...


 * Some basic information: Rilak (talk) 13:42, 16 September 2008 (UTC)

Oh, that looks great. Thanks. Going to take a little time to dig through it... Shieldforyoureyes (talk) 20:22, 16 September 2008 (UTC)


 * Oops! I forgot to mention that the document is mostly about the Starfire architecture, which is not used in the Sun4d, but it does mention the XDBus in a few places. A better source would be this paper: "XDBus: a high-performance, consistent, packet-switched VLSI bus", but unfortunately there are no free copies that I was able to locate. Rilak (talk) 09:30, 17 September 2008 (UTC)

SMP
I talk about SMP and memory access because it's easy for a modern computer user to look at this system and assume it's some sort of clustered blade server or NUMA machine. The point is that the memory and IO devices on each board are not more closely coupled with the CPUs on that same board than with the other CPUs in the system. If the CPUs on each board had faster access to the memory on that board than the rest of the system, it would technically be a NUMA architecture, not SMP.

The reason SMP processors can all perform the same tasks is that they all have equal access to the hardware.

That said, the SMP discussion in this section does ramble on, and should be edited down a bit.

Shieldforyoureyes (talk) 13:41, 14 September 2008 (UTC)


 * SMP simply refers to the fact that all CPUs are treated equally. What you are referring to, I believe, is Uniform Memory Access. Rilak (talk) 13:51, 14 September 2008 (UTC)

I'm talking about Hardware SMP, you're talking about Software SMP. UMA is definately a part of Hardware SMP.

Look at the "Differences between hardware ASMP & SMP" section of the ASMP article (which needs a link fixed...), and the introduction to the SMP article.

Shieldforyoureyes (talk) 14:15, 14 September 2008 (UTC)


 * I am not talking about software SMP. Where did I ever state I was referring to software? Rilak (talk) 14:26, 14 September 2008 (UTC)