Pentium Pro: The First To Handle Over 4 GB Of Memory
Source: Tom's Hardware – Keywords: intel, cpu, history
Pentium Pro: The First To Handle Over 4 GB Of Memory
The Pentium Pro, released in 1995, was the first x86 CPU able to manage more than 4 GB of RAM using Physical Address Extension (PAE), 36-bit address size, and thus 64 GB. An interesting point is that this processor was also the first P6 (the architecture the Core 2 processors are loosely derived from) and also the first x86 to include a Level 2 cache on the processor instead of on the motherboard. In fact, between 256 KB and 1 MB of cache were placed next to the CPU, on the same socket, making the L2 cache on-package as opposed to on-chip, clocked at the same frequency as the CPU.
This processor also had a bit of a performance issue. It ran great in 32-bit applications, but was much slower with software still written in 16 bits (like Windows 95). The cause was simple: access to 16-bit registers caused problems with management of the (32-bit) registers, which canceled out the advantages of the Pentium Pro’s out-of-order architecture.
| Code name | P6 |
| Date released | 1995 |
| Architecture | 32 bits |
| Data bus | 64 bits |
| Address bus | 36 bits |
| Maximum memory | 64 GB |
| L1 cache | 8 KB + 8 KB |
| L2 cache | external, 256-1024 KB (CPU frequency) |
| Clock frequency | 150-200 MHz |
| FSB | 60-66 MHz |
| FPU | built-in |
| SIMD | N/A |
| Fabrication process | 600-350 nm |
| Number of transistors | 5,500,000 + cache |
| Power consumption | 29-47 W |
| Voltage | 3.3 V |
| Die surface area | 306-196 mm² + cache |
| Connector | Socket 8 |
The cache measured 202 mm² (256 KB at 500 nm), 242 mm² (512 KB at 350 nm), or 484 mm² (1 MB at 350 nm). The number of transistors in the cache was 15.5 million (256 KB), 31 million (512 KB), or 62 million (1 MB).
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Wasn’t one of the key features of the Pentium Pro line of processors the increase in IRQs to 256 rather than the 16 of the previous generations?
In the days of virtual IRQs assigned by windows it's easy to forget the headache of trying to install multiple interface cards without running out of resources.
am I mistaken? or the Maximum memory figures are wrong? 4096MB or is it KB on 386, 486 and Pentium MMX class CPU's. and 64MB on P-II and so on.
Modern Intel CPU: P1-> P3 -> P4M -> C2D -> C2Q
Modern AMD CPU: P1(Intel) -> P3(Intel) -> K8 -> K10
Next gen CPU: Modified P1
The Pentium 1 & 3 are possibly the most widely base processor in modern computing. Even AMD's chips are based on them.
Hmm....
Interesting...AMD chips based on P3... EHEHEHEHHEHEHE
I think you need a...khhmmm...LIFE
cheers
Nice article that made me a little bit misty-eyed and nostalgic (being of the original 8086 generation)
Did a bit of a clear-out of my parts boxes not so long ago and found a couple of PPro's, a 486DX2/66, a 386SX and a 386DX. Threw them out but perhaps should have built a little shrine? ;p
Cheers.
There are some errors in the article, Pentium M Dothan had a 2.26GHz model which is not mentioned there, they had a VCore of 1.356V and a TDP of 27W, not 36W like stated here, also it's die size is 88mm2, not 87mm2, it also came as a socket 478 which was incompatible with the Pentium 4 socket 478 due to it's electrical differences.