AMD's 64-Bit Chip

EyesWideOpen writes "AMD is set to release a 64-bit chip early next year which will be completely backwards compatible with the Athlon line. The current 64-bit offering from Intel, Itanium, is an entirely new chip that has no backwards compatibility with its x86 line of chips (from the 8080 chip to the Pentium IV) and is designed only for high end servers. AMD's solution to this problem is the Opteron chip (product info) which will be in servers, desktops and laptops. Here is a wired article."

Comments

Breaking news!!

[_typo]

Slow day, huh?

AMD FUD

[bmorris]

Both the Itanium and the Itanium 2 will run x86 code. For details see: http://h21007.www2.hp.com/dspp/files/unprotected/i tanium2.pdf

Re:AMD FUD

[Perdo]

A dual 1Ghz Mac can emulate x86 and performs as well as a 266Mhz PII

A 667 mhz 64 bit Alpha can emulate x86 but is only as fast as a 200mhz Pentium Pro

An 800 Mhz Itanic emulates x86 as fast as a 166Mhz Pentium.

Linux can emulate a cluster on a single machine.

Any PC with two network cards can emulate a Cisco router.

Intel stopped marketing Itanium's x86 emulation mode because it is abysmally slow. The emulator is of course compiled on Itanium's still very immature compilers so it will improve in the future.

The Sledgehammer contains a complete x86 core and a complete 64 bit risc core. At 800mhz it outperforms a 1.6Ghz Pentium 4 running stock Windows XP and stock applications.

Running 64 bit SUSE, the Sledghammer performs as well as an Itanium at the same clock speed.

Sledgehammer is expected to ship at 2.0 Ghz. It's should perform as fast as a pentium 4 at 3.4 Ghz. Each processor has it's own memory controller so there is no shared memory bottleneck for multiprocessing. 2 processors should be exactly twice as fast using multithreaded applications. Sledghammer scales to 8 processors.

Re:Stability

[Anonymous Coward]

No, because the problem in Windows wasn't moving from 16 bit to 32 bit, it was moving from cooperative to preemptive multitasking.

Re:Of course backwards-compatible

[Gumber]

Of course, Itanium is backwords compatible with x86 code. It just isn't particularly fast when doing so.

Apple's 68K migration

[neye_eve]

The only time I've seen a successful migration from one platform to another was when Apple managed to migrate from 68K up to PowerPC, and that was only really possible because they controlled both the hardware and the software.

they were also successful because in part so many developers spent a lot of time making fat binaries that would run on either 68K or PPC platforms. The developers made things backwards and forwards compatible at the same time in one package.

neye

ARM and Thumb instruction encodings

[yerricde]

"64-bit code is twice as big as 32-bit code" bloatware excuse

Unfounded. Though I find Itanium's instruction coding (16 bytes per 3 instructions) bloated, not all high-"bit" machines have to have bloated bytecodes. The ARMv4 architecture, used in processors such as the ARM7TDMI in the Game Boy Advance, has a standard 4-byte-per-instruction encoding, and an optional 2-byte-per-instruction encoding called "Thumb". Thumb code runs at about two-thirds of the speed of ARM code on machines with fast memory because some operations take more instructions on ARM than on Thumb, but Thumb code really shines when running on small or slow memory and can help drain less battery power on mobile machines. Apps will often have most of the app in Thumb but some of the time-critical inner loops in ARM.

First 32-bit processor came out in 1995?!?!?

[blakespot]

Staggering quote from the Wired article, effectively rendering the author's opinion moot:

• "While the first 32-bit processor came out in 1995, the average PC used 1 MB of memory, so 4 GB was both unaffordable and generally not needed."

Without digging too deeply, it can be found that Motorola came out with the 68020, a true 32-bit processor, in June of 1984, 11 years prior to the debut of the 32-bit processor according to the nimrod author. I don't have solid dates but I know that within a year of this timeframe Suns and Apollo workstations were using this chip.

How disgraceful.

blakespot

Re:First 32-bit processor came out in 1995?!?!?

[Dave9876]

Motorola came out with the 68020, a true 32-bit processor, in June of 1984

So? The VAX came out somewhere around 1978, and it was also a 32bit processor, and DEC had been doing 36bit processors for a long time. I think you'll find there's more out there if you just look a little harder. Computing didn't start in 1980, just like 32bits didn't just appear in 1984.

Other Wired article errors

[clem.dickey]

The Wired article has other errors as well. A 32-bit CPU isn't limited to 4GB; that confuses address space with physical memory. The definition of exabyte is wrong (1000 petabytes, not 1000 terabytes). The 8080 in 1981? Closer to 1975. And many have mentioned the bogus "no compatibility" claim.

One wonders if the whole thing wasn't a troll.

Itanium *IS* x86 compatible.

[Anonymous Freak]

Just not the way you might think. An Intel Itanium-based computer running Linux64, Win64 (the codename for the 64-bit version of Windows 2000) or Windows XP 64-bit can run x86 (386, Pentium, Pentium Pro, etc) binaries unmodified. It will be significantly SLOWER than an equivalent x86 processor, because it does do it via hardware emulation, but it does do it.

Where the Itanium (and, I'm assuming, the Opteron/64-bit Athlon) really matter is in in large database and high-end workstation solutions. Basically, anything that needs more than 4GB of RAM. In these uses, it's not actually the processor speed that is needed, it's the RAM. The Itanium is meant for servers, yes. That is all the Itanium was designed for.

The cleverly named Itanium-2, however, is a horse of a different color. Not only is it faster (both MHz and IPC,) but it's cheaper, too! (You can get an Itanium-2 based system for about $3000.) The Itanium 2 at 900MHz is about twice as fast as the 'old' Itanium at 800MHz, performance-wise.

The only thing AMD has going for them (literally) is x86 compatibility. If it can run x86 code reasonably fast (i.e., a 1GHz Opteron running Pentium code at least as fast as a Pentium 3 1GHz) then it will be likely to take over the Workstation market from the Itanium 2. Unfortunately, I don't think anything could cause the Opteron to win over Itanium 2 in the high end server market.

Re:MODERATORS ON CRACK

[TheOnlyCoolTim]

If your motherboard was designed right, it would notice the overtemperature, react, and shut it down. The real problem is the heatsink falling off- if that happens, your CPU will emit magic smoke faster than the temperature sensor can react.

Tim

Re:36 years early!

[Anonymous Coward]

I think what he's referring to is when the number of seconds since 1970 (Epoch) will overflow a 32bit integer

Re:Since when is the 8080���

[quade_79]

um, here's the straight dope©©©

• 8086 -> first sucessfull intel 16 bit chip© it had a 16 bit data buss, and a 20 bit memory buss, though unless you liked keeping track of the segment pointer, it was limited to 16 bits of address
• 8088 -> quick addition to the 8086, it was an 8086 with a 8 bit external data buss, but still 16 bit registers
• 80186 -> little known chip, it was an 8086 with much of the supporting circuitry integrated
• 80286 -> Intel's first attempt at a real CPU like those found in a VAX or PDP-11© It had a broken virtual-memory mode, and some protection schemes© It was still a 16 bit CPU with 16 bit registers, and a 16 bit datapath, but it had a 24 bit address buss, allowing for 16 Meg of memory© However it used a new buss protocall that was twice as fast as the 8086
• 386 ¥DX -> Intel's first real CPU© 32 bit registers, 32 bit data buss, and 32 bit address buss© It had hardware memory management, memory protection, and working virtual memory© this is where ia32 started© It had two mode Real and Protected mode© In real mode, it acted almost exactly as a 286/8086 would, in protected mode, it had all the goodies
• 386 ¥SX -> essentialy a 386 in a 286 body© It was almost pin-compatible with a 286 , but it was code compatible with the 386
• 486 - faster 386 with a built in FPU ¥except the SX version and it had a burst mode memory buss

Re:Mod Parent down

[FrostedChaos]

Unfortunately, AMD chips do tend to be less reliable than Intel chips, for several reasons:

1) Lack of a thermal diode. The CPU will burn up easily if the heat sink falls off, even partially.

2) Cheaper packaging (this has to do with the construction of the cpu)

3) Cheaper motherboards. A bad motherboard is a bad investment, no matter how low the cost is. Don't buy a Via.

None of this should prevent people from buying AMD, but it is something to think about.