The shared L2 cache, at 1MB, is fairly small considering there is no 元 cache. Optimizing compilers can only do so much, and instruction streams meant for in-order processors should always run faster on out-of-order processors like the x86. Xenon uses in-order execution - great for simple/cheap/power-efficient hardware, but bad for performance. May mean x86-64 only, or letting some other layer do the work if 32-bit compatibility is a must. #Best xbox 360 emulator for pc toms code#Emulating 64-bit on 32-bit instruction sets (such as x86) is not only significantly more code but also at least 2x slower. Xenon is 64-bit - meaning that it uses instructions that operate on 64-bit integers. There are some considerations to take into account when translating the instruction set and worrying about performance, highlighted below: Building a translator for PPC to x86-* is a non-trivial piece of work, but not that bad. The PowerPC instruction set is RISC - this is a good thing, as it's got a fairly small set of instructions (relative to x86) - it doesn't make things much easier, though. ~96GFLOPS single-precision, ~58GFLOPS double-precision, ~9.6GFLOPS dot product L1: 32KB instruction/32KB data, L2: 1MB (shared)Įach core has 32 integer, 32 floating-point, and 128 vector registersĪltivec/VMX128 instructions for SIMD floating-point math They'll cover the CPU, GPU, and operating system.Ħ4-bit PowerPC w/ in-order execution and running big-endian The next few posts will investigate each core component of the system and try to answer the two questions above. Although it's not going to be a piece of cake and there are some significant differences that may cause problems, this actually isn't the worst situation. The hardware is all totally custom (CPU/GPU/memory system/etc), but roughly equivalent to mainstream hardware with a 64-bit PPC chip like those shipped in Macs for awhile and an ATI video chipset not too far removed from a desktop card. The Xbox 360 is an embedded system, geared towards gaming and fairly specialized - but at the end of the day it's derived from the Windows NT kernel and draws with DirectX 9.
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