I am taking a distance education program for PC repair. I am currently doing a unit on CPU's. IIRC, the main reason why we are moving to 64-bit is because 32-bit processors can only address 4 gigs of ram. The text book i am studying from says the 486, pentium 1, and pentium pro can address 4 gigs, but pentiums 2,3 and 4 can address 64 gigs with the proper chipset. so i ask, if this the case, why bother moving to 64-bit?
This is the first I've heard of that. Unlike AMD's processors, I thought Intel has the memory controller on the chipset, perhaps it can manage more addreses that way? And as for moving the whole kit and kaboodle to 64 bit, twice as much data can be moved for every clock cycle. This is a more efficient than just increasing the clockspeed of everything (processors, front side bus, pci bus etc...).
When in doubt, gas it!
64bit = more speed in everythng. That pretty much sums it up.
I believe that you might've glossed over the distinction between physical memory and virtual memory. Either that, or the course you're taking is rather shady...
FWIW, 64-bit CPUs can address 16 exabytes worth of virtual memory.
i did not, C38368. it says it right from my text book, "if the chipset supports it, the Pentium 2, 3, and 4 can address 64 gigabytes of RAM". They are not talking about virtural memory, they are talking about physical RAM. I think this has to be some mistake. I'll email my teacher
Book's wrong, then. Or at least incomplete. AFAIK, the CPU doesn't know the difference between physical and virtual memory, but that 64GB figure refers to virtual memory only.
Wow...ya...I think the text book is wrong also, 64 gigabytes? good luck finding a comp that can take in 64 gigabytes...that is rediculous...And yes, 64-bit will handle your RAM much better, I would always think that faster RAM can be better then more RAM.
I agree with you Mitter and C38368. I did email my teacher about it, no reply, yet.
I love you Dragokatzov...your the first person to address my name in that manner...everyone else is so mean to me...haha, well thank you. Plz get back to us on what your teacher has to say on this, it would be very much appreciated.
Shizzle my nizzle
28th July 2004
Technically, a 32-bit processor could have 64GB of addressable memory, if the word length (32-bit) referred to the size of the address bus, not the data bus. The amount is calculated as follows:
Maximum Addressable Locations = (2 ^ [Address Bus Width]) * [Data Bus Width]
So if an address bus was used higher than 32-bit, then it could be possible to have 64GB of addressable memory. However, it is quite silly to use an address bus different in size to the data bus (equal in size to the word length), as it will never use more than the amount the data bus uses (32 in this case).
The book is however wrong in saying Pentiums can address such a quantity. They can't. It can be done, though.