64 bit the way to go?

Fabritzo

I'm thinking of upgrading

Does anyone know their stuff about
Athlon 64 3200+
AMD Athlon 64 (Clawhammer) Socket 754
3200+ (2Ghz) QuantiSpeed Technology
int. 128KB L1 cache, 1024KB L2 cache (full cpu speed)
200(400)Mhz System Bus Speed
(marx computers)
I'm assuming regular pci/agp cards can be put a motherboard that supports the 64 cpu?
And what about ram?

po0k

Originally posted by Fabritzo
I'm thinking of upgrading

Does anyone know their stuff about
Athlon 64 3200+

AMD x86-64 chip, the average joe consumer model, the A64fx being for the enthusiast and the Opteron being for workstation/server Uni- or SMP configurations.
The "ordinary" Athlon64 is still bloody nippy at the moment and afaik unlike the Athlon64fx (which is essentially an Opteron 14x) supports DDR400 and doesn't demand ECC ram.
They work essentially the same as current x86 chips (in terms of what you put in and what you get out), but have deeper registers etc. which are neccessary for 64-bit calculation.
Windows2000/XP can't take advantage of 64-bit cpus because they're only 32bit OSes.
The only platform you'll currently see the benefits of having an Athlon64 chip is under a 64-bit flavour of Linux/some other UNIX-type OS or a beta version of Windows Longhorn. There is a 64-bit version of WindowsXP but afaik that's designed to run on Intel Itanium chips (64-bit but it's EPIC IA64 not x86-64 instruction set).
Apparently Microsoft has a 64-bit version of some Windows OS (XP Service Pack2 anyone?) which will probably be Longhorn....when it comes out.
intel has also said that the new generation of pentium chips will have 64-bit extensions and reports from a few tech sites (namely El Reg) have found that though they won't be 100% indentical implementations, it will be transparent as far as windows programs are concerned.

AMD Athlon 64 (Clawhammer) Socket 754

It's what's above. The Athlong64 currently comes in a socket754 package, and the Athlon64fx and Opterons come in Socket940 package.
Very soon (in the next 2-4 months) the Athlon64 and 64fx will be migrated to Socket 939, not 100% sure about the opterons. The reason for this migration is to sort out memory issues and distinguish the consumer-level chips from the enterprise ones.

3200+ (2Ghz) QuantiSpeed Technology

Quantispeed is a tech first introduced with the original AthlonXPs. Means bollox-all to be honest and has nothing to do with 64-bit.

int. 128KB L1 cache, 1024KB L2 cache (full cpu speed)

internal 128Kilobyte of Level1 cache is the amount of very high-speed, high-bandwidth buffer memory the cpu has to keep very regularly accessed chunks of data close at hand.
Level 2 is generally bigger, slightly further away and may not have as much bandwidth.
They're "internal" meaning they're part of the CPU die and are SRAM (static ram) made using transistors.
As such they're far far faster, bigger and more expensive than main memory (which is DRAM or Dynamic RAM) which is made with capacitor-type technology, slower than SRAM, can be made more densely (hence you being able to buy a Gigabyte (1024MegaBytes) of DRAM on a stick maybe 100 times larger than the 1meg of L2 cache on the cpu).
DRAM also consumes far more power as it needs to be constantly refreshed to retain the data whereas SRAM is kind of "held" in place. The refreshing process of DRAM is where the CAS, RAS and RAS-to-CAS timings come into play, the number of clocks (hz) needed to check and set the Columns (Column Address Strobe) and Rows (Row Address Strobe).
"full-speed" means the L1 and L2 cache ram runs at the same speed as the cpu itself, as it's integrated in the core. The early Pentium3s (Katmai cores) and orignal AMD K7 Athlons were the last consumer chips to have external L2 cache (the cache chips were slapped on the cpu board alongside the actual CPU core) and were generally run at half the cpu core speed or less. This proved problematic for overclocking, particularly when your cpu had "poor" quality cache chips, not to mention the performance hit of having to wait for this slower cache in normal operation.
more and more things are starting to move closer to the CPU and become more integrated.
Another feature of the Athlon64/Opteron is that they don't need a northbridge as such, they have the memory controller built into the cpu die.
This is great from a performance point of view, but can be a hinderence when newer/fast memory technologies come out as the cpu will literally have to be redesigned each time, instead of just developing a new (external) northbridge/motherboard chipset.
This will neccessitate replacing the CPU, RAM and motherboard to upgrade instead of just one or 2 components.

200(400)Mhz System Bus Speed

200Mhz refers to the speed at which the CPU and northbridge chip on the motherboard communicate, and is called the FSB or Front Side Bus.
the 400 is in brackets as on AthlonXPs they're "dual-pumped" ie transfer data on both the rising and falling edge of the clock tick and so get double the data through for every clock cycle.
DDR RAM does a similar thing aswell, which is why memory/FSB speeds are generally said to be twice what they *really* are.
when shopping for ram, cpu and motherboard this is how things play out:
100Mhz FSB => 200Mhz effective/400Mhz on P4s => buy PC1600 DDR (1.6GByte/sec bandwidth, DDR200)
133Mhz FSB => 266Mhz effective/533Mhz on P4s => buy PC2100 DDR (2.1GByte/sec bandwidth, DDR266)
166Mhz FSB => 333Mhz effective/667Mhz on P4s => buy PC2700 DDR (2.7GByte/sec bandwidth, DDR333)
200Mhz FSB => 400Mhz effective/800Mhz on P4s => buy PC3200 DDR (3.2GByte/sec bandwidth, DDR400)

The reason P4s seem to have double the effective FSB speed is because while Athlons are "dual-pumped", Pentium4s are "Quad pumped".
Because of this P4s will see far greater benefits from installing DDR in pairs or "dual-chanell mode".
Athlons will only see maybe 5% increase in memory bandwith as the second DDR memory channel effectively fills up any little gap left by memory overheads with the first channel.

Afaik the Athlon64s are currently still only dual-pumped while the Athlong64fxs are quad-pumped.

(marx computers)
I'm assuming regular pci/agp cards can be put a motherboard that supports the 64 cpu?

right now if you go and buy a socket 754 athlon64 you've got 2 choices for motherboard platforms;
the nVidia nForce3 150 and the VIA KT800.
They both have regular PCi and AGP slots.
Again, in the next 2-4months you'll start to see the first "proper" PCI-Express motherboards arriving which will wrap in a pile of other new technology changes (Sata2.0, DDR2/3, 64-bit [socket939] etc.).
These boards may/may not retain AGP or PCI slots, and it'll more than likely be ordinary PCI slots they'll have, if at all (maybe universal PCiX slots: 64-bit 66Mhz-133/266Mhz, mainly used in workstations and servers).

And what about ram?

Right now the Athlon64 on the two afore-mentioned chipsets will run with ordinary bog-standard DDR memory (DDR400/PC3200 or better)

hope that answered all your questions

leeroybrown

The funny thing is that it's _not_ the 64 bit extensions that make 64 bit chips fast, it's the improved CPU design that we are getting as part of the package that is doing that.

64 bit CPU's have advantages such as being able to natively address huge memory spaces, being able to work with more threads, being very good at intensive floating point math, but if you're not taking advantage of of these traits then typically they are the same speed or slower (maybe ~ 1 - 3%) due to the much larger cache footprint.

As an example, Sun's Solaris (SPARC version) which is designed to run on a 64 bit architecture ships with almost all the packages complied as 32 bit binaries. Only libraries and applications that are advantageous to run as 64 bit code are made available as 64 bit binaries.

If I were to buy an Athlon 64 the main reasons in my mind would be the performance of it in 32 bit mode and the very large LI (128Kb) and L2 (1Mb) cache sizes.

Matt Simis

Originally posted by SyxPak

The only platform you'll currently see the benefits of having an Athlon64 chip is under a 64-bit flavour of Linux/some other UNIX-type OS or a beta version of Windows Longhorn. There is a 64-bit version of WindowsXP but afaik that's designed to run on Intel Itanium chips (64-bit but it's EPIC IA64 not x86-64 instruction set).
Apparently Microsoft has a 64-bit version of some Windows OS (XP Service Pack2 anyone?) which will probably be Longhorn....when it comes out.
intel has also said that the new generation of pentium chips will have 64-bit extensions and reports from a few tech sites (namely El Reg) have found that though they won't be 100% indentical implementations, it will be transparent as far as windows programs are concerned.



The reason P4s seem to have double the effective FSB speed is because while Athlons are "dual-pumped", Pentium4s are "Quad pumped".
Because of this P4s will see far greater benefits from installing DDR in pairs or "dual-chanell mode".
Athlons will only see maybe 5% increase in memory bandwith as the second DDR memory channel effectively fills up any little gap left by memory overheads with the first channel.

Afaik the Athlon64s are currently still only dual-pumped while the Athlong64fxs are quad-pumped.

hope that answered all your questions

Just two additions:

There is the Beta version of Windows XP too (not just longhorn). The Reg is correct, its based on Windows 2003 not vanilla desktop XP variants. You can get it and Lornhorn (32/64bit) via MSDN currently. You can also download Windows XP 64bit for free via MS's open development program.

Id stay away from oldschool comparisions of FSB when talking about AMD64. As the memory controller is integrated, only the PCI and AGP bandwidth shows much difference when changing the Hypertransport (aka Lightning Data Transfer) bus speed. The bus runs at 600MHz (double pumped) on the nF3 and 800MHz (again double pumped) on the K8T800. This is why you sometimes see AMD64 boards marketed as "1600MHz FSB". Both the Athlon64 and AthlonFX have the same HT bus speeds (and both are "double pumped", ie 16bit, see below). The nF3 250 is rumoured to have a 1000MHz (dbl pumped) bus.

For example, the HT bus on a nF3 is 600MHz, the confusion arises as the BIOS exposes the bus as:
200MHz x 3x (3 is a multiplier, not a "pump" value), running in either 16bit or 8bit mode (these modes are the "pump" values, obviously 8bit is a "1x" pump).
200MHzx3x16bit = "1200MHz FSB"

There are no doubt some inaccuracies or simplifications in what I posted, but you get the idea!



Matt

Fabritzo

Hmmm, you remind me of the guy with the glasses in the dell ad, but I did ask. The 64bit processor seems a bit new to be buying yet(i.e. not supported), I really just want a mobo, cpu and ram that I won't have to worry about changing for 3 years, on a budget of ~400, I'll buy a psu separtely and have the other bits to make it work.

Matt Simis

Originally posted by Fabritzo
Hmmm, you remind me of the guy with the glasses in the dell ad, but I did ask. The 64bit processor seems a bit new to be buying yet(i.e. not supported), I really just want a mobo, cpu and ram that I won't have to worry about changing for 3 years, on a budget of ~400, I'll buy a psu separtely and have the other bits to make it work.

Thats a bit of a contradiction isnt it? You worry that the AMD64 is too "new" to buy, yet want a system that still offers some punch in a couple of years... seems like the Athlon64 fits that bill nicely! You dont need to concern yourself with the 64bit'ness at the moment, just the fact it offers great speed on everything you currently do.

Then, in a couple of years when Longhorn is out, you will be able to switch to the "better" version (it will be released in both 32 and 64bit versions), for presumably no additional cost to you (over purchasing the 32bit version).

Buy a P4\AthlonXP on the otherhand, and it doesnt get any better with age.

Your budget might be cutting it a bit tight however.


Matt

leeroybrown

AMD are replacing their entire CPU lineup with x86-64 based chips. Essentillay, they are their new high performance chips and is their current platform.

Intel on the other hand are taking the view that the consumer market is still adequately served by 32bit computing (most home users won't be able to make use of the 64 bit extensions extensively for a while yet).

The main bonus of the Athlon64 for a home user is that it offers excellent 32 bit performance as well as native 64 bit computing. There's no issue with it being "supported". Every current piece of 32 bit x86 software will run on it considerably faster than it would have run on a similar clock speed AthlonXP.

As Matt mentions your budget may not stretch. The Athlon64 boards are sightly dearer than AthlonXP or P4 equivalents and byt he tiume you throw in RAM you'll be past €400.

(Also, this thread should be in Technology)

RicardoSmith

Originally posted by Matt Simis
...want a system that still offers some punch in a couple of years......Then, in a couple of years when Longhorn is out, you will be able to switch to the "better" version ...

PC's don't have a long lifespan. After the first year they are midrange. After 2 years they are low end and after 3 years they are obsolete.

po0k

If you're goig buying a machine with a bit of future proofng in mind, work over the summer and save your cash.
Get a grand and in september buy a "new" next-gen system (64-bit, PCI Express, SATA2 etc.).

It'll still be serviceable and expandable to a certain degree 18 months later.

2004 is the year of "the shift".
You don't want to get caught on the wrong side of it

Matt Simis

Originally posted by RicardoSmith
PC's don't have a long lifespan. After the first year they are midrange. After 2 years they are low end and after 3 years they are obsolete.

Heh, I know that, but Fabritzo wants to get the longest out of his quickly depreciating purchase. I do think an A64 would be slightly less obsolete than a P4/XP however.



Matt