Some CPU funda's 101 ........
The cpu core consits of cpu register pairs ( Accummulator (AX), Base Index (BX), Counter (CX) Data (DX) Extra segment (EX) (Stack Segment SS), (Instruction register (IX) Program counter (PC) buses and logic circuits mostly NAND based....... (Duh! NAND being the Universal Gate) The importance of cache is that it is on the same speed as that of cpu registers...
You want cpu to perform a function it goes like this ...
Fetch, Decode and Execute... with a fetch execute being overlapped ... to increase performance... The cpu operates in cycles ... The data is loaded into the registers pairs and operated upon and transfered... the PC gives the address of next instruction which is loaded into the cpu registers and then executed...... The bits of these registers signify the bits of the cpu and hence the instruction and the data processed by them .... suppose a cpu is 8 bit then max no of instrction that can be given to it 2^8 and for 64 bit this becomes 2^68 that are a hell lot of instruction the instruction set does not have so many instrcutions heck they do not have even 2^32 no of instruction... what might be they can operate with 64 bit data now which they previously did by placing the LSB and MSB in two diffrent registers... Then there are micro program controlled and RISC based systems we use microprogram controlled that needed decoding so that cpu performs them in terms it understands.....
you might have heard of 32 bit binaries meaning they can be executed by a 32 bit cpu as both the data and instrcution are in 32 bit only... now how does a 64 bit procy does the same simple the registers are 64 bits so MSB is filled with leading zeros and it works by using LSB's only now if a 64 bit binary is there then it needs to place MSB aand LSB in diffrent registers and works with 2 register pairs now for single piece on data (Hence the over head but 32 bit cpu will execute 64 bit binaries it is upto OS to make it understand HOW??
Thanks for your informative post,appreciated
....Here comes my doubt .. Somebody plz tell me why the Heck Itanium Sucks in performing 32 bit Instructions... Under no circumstances it will make sense)
Well i am not a architectural guru as you but i know some things for sure.Itanium itself was never bad,it was MEANT to be a 64 Bit CPU and apps needed to be recoded to make full utilisation of its potential.Intel had embedded support for 32Bit apps but it was emulated and hence the performace took a major hit.The hit was so bad that even the Itaniums younger siblings, Xeon and Pentium surpassed it.Mind you the Itanium was insanely expensive.during that time, most of the apps were written in 32bit and not 64bit cos there were no CPUs for it.So although large corporations adopted Itanium,smaller ones just couldnt because of the cost factor and the 32 bit performance issue.It is a well known fact that the Itanium's debacle is attributed to this inability to run 32bit apps efficiently.Then came Opteron and it offered Hybrid 32-64Bit support and it did it efficiently.It made sense to make a massive Opteron based clusters and get insane performance boosts. Since the K8 was a 64bit architecture,its memory controller could address insane amount of Memory and that too at incredibly low latencies.This hit the Itanium the worse.Even Intel started concentrating on Xeons ,the same way as AMD did,to go the cluster way.Itanium was Intel's most cherished and ambitious project but it failed to pick up.
Link - Itanium 32bit deficiency
^^ Not a proof or anything,just to give you idea that even Intel had agreed to Itanium's poor 32bit performance.
AMD cpu exectes 10 calculations
Are you talking about IPC [Instructions per clock cycle] ? If that is the case then, K7 had 9 IPC compared to 6 IPC in Pentiums.
After i shift into my new flat i will answer all the queries (As i will have more time then) @DL AND all your LOL's too nothing personal but i think that people should understand a cpu and not go on the marketing gimmicks of some HIGH SOUNDING WORDS LIKE SMARTCACHE.. PIPED SIMD AND NETBURST... these are all simple technologies ... yeah it improves performance but not necessarily you use that.........
You have noble thoughts and intentions my friend but as people like you or me might be 'interested' in going a bit deep,others are just not bothered or maybe they dont have time or they just dont understand.So we should come up with a simple conclusion for such people regarding a particular product.Thats my outlook, hope you understand
Regarding your logic of Product naming,well i dont think it works that way,here's why i think so,
You say,
AMD Athlon XP 2000+ [1.67 x 10 x 1024 = 17,100.8] Vs. Intel Pentium 4 2.0 GHz [2.0 x 8 x 1024 = 16,384]
Clearly 2000+ has a larger value than P4 2.0GHz,right ?
Ok now please explain these scenarios -
AMD Athlon XP 3200+ [2.2 x 10 x 1024 = 22,528] Vs. Intel Pentium 4 3.2 GHz [ 3.2 x 8 x 1024 = 32,768]
You see P4 3.2 gets a bigger value than the AMD value.
Next,
AMD Athlon XP 2800+ , 3000+ , 3200+ all had multiple versions and they had different clock speeds,
1] AMD Athlon XP 2800+ --> 2250MHz(Thoroughbred Core,266FSB) ,2083MHz (Barton Core,333 FSB) , 2133MHz (Barton Core,266 FSB)
2] AMD Athlon XP 3000+ ----> 2100MHz(Barton Core,400FSB) ,2167MHz (Barton Core,333 FSB)
3] AMD Athlon XP 3200+ -----> 2200MHz (Barton Core,400FSB) , 2333MHz (Barton Core, 333 FSB)
Same model nos. but different clock speeds,how ?? Doesnt make sense.
Well no offense but i know i am not architectural or computing guru but whatever facts i post are atleast true. If i am unsure of something,i do not post it.Its better to not post rather than posting wrong info
As far as product rating goes, well even Intel chucked the clock speed thing long ago and rates their products.How did that happen ?
Seriously dude,nothing personal here just sharing info and correcting some wrong info people post here.Take it in that spirit.The 'LOL' and 'ROFL' are for those who post wrong info,concepts with such authority,it amazes me.
I hope you understand my intentions and take them in the right spirit.
Hope to share knowledge with ya
Darky
