CPU Model Differences?

[David Meek]

Showing my PC-illiteracy big time here. Be gentle. . . .

What are the differences in the various types of processors available in PC's today? If I wanted to go with say, a 2.8 GHz chip, what would be the benefits of using a P4? What would be the benefits of using a Celeron? Or an AMD?

Signed,

Vastly confused in Windowsland

[Kevin P]

Well, to start with there's two major manufacturers of CPU chips: Intel and AMD. Each has a wide range of processors ranging from entry level to high-end (read: expensive).

In general, AMD chips at a given clock speed are faster performance-wise than Intel chips. So, for example, a 2.2 GHz Athlon 64 performs roughly the same as a 3.5 GHz Pentium 4. But your mileage may vary depending on what you're using your PC for. The P4s tend to fare better in applications such as video editing where large amounts of data need to be fed between RAM and the CPU, due to the P4's high-speed memory interface. The Athlons are faster in raw number crunching, gaming, things like that.

Within each manufacturer there are several lines of processors. Intel has, from lowest to highest, the Celeron, Pentium IV, and Xeon lines. AMD has the Duron, Sempron, Athlon (including AthlonXP and Athlon64) and Opteron lines.

As for speeds, they are even more confusing. Intel speeds are measured in clock speed (e.g. 2.5 GHz). AMD uses a number that roughly corresponds to the equivelent Intel clock speed. For example, an AthlonXP 2200+ runs at 1.8 GHz but is roughly equivalent to an Intel P4 at 2.2 Ghz.

Confusing enough for you so far? If you have more specific questions I can go into more detail. There's a ton of other parameters such as socket type, core type, FSB speeds, L1/L2 cache sizes, etc. I figured I'd start you off easy.

[aud19]

Get AMD, they're better :T

:lol:

Jason

[brucek]

Get AMD, they're better

But, there are those who feel INTEL chips are more compatible with all applications. 8O

brucek

[Kevin P]

But, there are those who feel INTEL chips are more compatible with all applications. 8O

That might have been true a few years back but not so much today... AMD chips execute the same instruction set as the Intels, with only superficial differences (e.g. 3DMAX vs. MMX vs. whatever).

For those who remember Cyrix processors, those caused a lot more issues than AMD ever did. :roll:

[aud19]

I've got a stutter, get AMD, they're better AND more affordable. :lol:

Jason

[ThomasW]

I don't know of any modern software that's incompatible with the current AMD chips.

I haven't owned an Intel CPU since Celeron 300's were a state of the art processor (and that was a while ago :E ) .

And the current Athlon 64's absolutely kick butt!

JonMarsh runs some of the most processor intensive programs on the planet (Auto-CAD 3D, Protel, SPICE, etc). He prefers the AMD chips.

Since Intel has been unable to get their 64 bit extensions to function reliably, Intel has been forced to adopt (and pay for) AMD's 64 bit extensions. Doing that must gall Intel to no end ....... :roflmao:

[Andrew Pratt]

For those who remember Cyrix processors, those caused a lot more issues than AMD ever did.

Remember them... I owned several ops:

[aud19]

I don't know of any modern software that's incompatible with the current AMD chips.

JonMarsh runs some of the most processor intensive programs on the planet (Auto-CAD 3D, Protel, SPICE, etc). He prefers the AMD chips.

Yup I run a boatload of Corel and Adobe graphics programs, Autocad, Autodesk Viz 4.0 all on an AMD machine. Since I've been working here I've slowly replaced any old units with AMD machines and haven't looked back.

Jason

[brucek]

replaced any old units with AMD machines and haven't looked back

I guess you guys have your minds made up on this one... :roll:

I've decided after January it'll be about time to build a new computer, since I'm presently using an old AMD K6-350. My beginning research on the type of motherboard and CPU have led me to believe the INTEL is the way to go, but I could certainly be wrong.

I know AMD is a bit less expensive, but I thought AMD was a little behind the curve in offering (do they have it yet) the PCI express bus. Intel certainly has been offering it for a while. This seems to be a must have.

And does AMD even offer DDR2 240 pin memory with its higher bandwidth while INTEL supports both DDR2 and DDR. I think for the future I want something that supports the higher bandwidth memory.

I also understood the new INTEL P4 Extreme Edition CPU gives the Athalon 64 a run for its money. I've read a lot about Hyper Threading with the INTEL products - seems the way to go.

I don't do gaming, but I do a lot of Photoshop type stuff.

I have been considering the INTEL D925XCVLK Socket 775 ATX Motherboard with PCI Express, DDR2 Support, Gigabit LAN / USB 2.0 / Firewire / Serial ATA / RAID / Prescott Support.

Any comments - good or bad.........

brucek

[ThomasW]

Ken,

All depends on your priorities. If your goal is to spend the greatest amount of money for everything in the PC, then you're well on your way with those state of the art pieces of Intel gear...... of course you know it will all be 1/2 the original price in just a few months.

Personally I freak out at the thought of spending $500-$600 for a CPU, when in 12-18 months it will cost 1/2 that. So I buy/build my PC's with the idea that the CPU cost will be about $200(or less). I upgrade when the CPU speed has doubled and the cost for the doubled speed is again ~$200. Yea it keeps me a little bit behind the high speed curve, but I sleep well at noc and get a new PC (the internals anyway) every 18-24 months.......

Unless you're doing video editing, are a gamer or doing extreme number crunching, why bother with a maxed out PC?

If you're used to a 350, then a lowly 2.2 gig Athlon is going to seem like a ride in Burt Rutan's latest toy ....... :wink:

[JonMarsh]

Hey Bruce,

Your points are all valid, but then there are other factors, too. It depends a lot on what you want to do with your system, and what your overall goals are.

AMD is a little behind on PCI express, because they are supporting 3rd party companies to do it, not doing it themselves. nVidia, VIA, and SIS will be shipping solutions in November in volume. Personally, the only PCI Express solution I've seen that I found intriguing and not available on AGP is the nVidia 6600; but then, the higher performance 6800 is available in several flavors, some selling in the $299 range. Either way, PCI Express is in it's infancy as far as being a big system factor for desktop usage- IMO. YMMV.

Memory bandwidth is a curious thing. P4's certainly need as much as they can get- something about the overal architecture, including branch prediction and pipeline depth. Intel, when first introducing the P4, had a in interesting scientific benchmark program published on their site, showing how much more bandwidth the early P4 could use than the PIII. In fact, the P4 system was using 2X the overal memory bandwidth of the PIII. Impressive, for sure, if memory throughput floats your boat. The thing which wasn't highlighted, but which wasn't concealed, if you looked closely, was that the P4 ran the benchmark only 10% faster than the PIII, while gobbling up all that memory bandwidth. Hmmmm. Sort of like a Ferrari V8, compared with a small block Chevy?

The newest P4 Extreme editions are one hot chip, that's for sure- in more ways than one. I'm a Power semiconductor applications engineer for a company heavily involved in computing power application, including VRM and VRD solutions- I've got all the yellow books from Intel, if you know what that means. The P4 Extreme edition is one real headache for MB designers, because to validate a MB for that product (which is required for VRD 10.1 platform certifcation) requires the ability to deliver 119 A at CPU VID, with a load regulation line of 1 milliohm. Nasty. Do you have any idea how hard it is to put 119 A through a typical 4 layer 1 oz cu MB to the CPU socket with tight regulation, dynamic as well as static?

One thing I'm pretty impressed about is AMD's Cool and Quiet power management for the A64 processors, both desktop and mobile. My desktop, since upgrading to a PR3400 A64, is the quietest it's been in years. Average power and thermal load is quite reasonable- it seems they're using the same technology as in their mobile chips.

I recently was in the market for a new laptop/desknote, preferably widescreen model with DVD burner. I ended up picking up a Compaq Presario at a very nice price. PR3200 A64, DVD burner, 512 MB, nVidia graphics to go, 60GB HD, wireless G built in, 1280X800 widescreen. The really amazing thing is the battery life- it's even longer than my AMD Mobile Athlon, which could do 3 hours regularly- I'm getting four hours playing back DVD's, and 5 hours plus doing text work, presentations, email, browsing, etc. For comparision, a friends Sony GRV680 is lucky to manage 1-1/2 hours with their biggest battery, doing anything. That system has a 2.6 GHz P4M.

Some of the improvement in the compatibility situation is due to the fact that AMD has SSE support and MMX support as well as their own graphics extensions. The newest P4's are potentially faster on some floating point work IF the software is properly coded for SSE3, but if it uses the normal X87 code, the AMD's seem to have the upper hand- full dual floating point units.

The other factor for the AMD64 which has led to a relatively fast ramp up in the scientific and server market compared with their previous presence is the use of the Hypertransport interconnect for cross CPU communication and memory. The P4 architecture doesn't have anything comparable, and as a result, memory bus bandwidth becomes a problem; the Athlon 64's scale very well to two and four way systems and beyond. This is why Intel's quotes about it being "about the platform" when comparing there Nocona CPU's to the Opteron's sound funny to a number of people.

And I hear that Intel will have the NX bit implemented by November or so in shipping EMT64 architecture machines. Another first for AMD in X86 space, though Intel has had it in the Itanium. They didn't want to put it in the X86 series, becuase they were using marketectural differences to justify the Itanium over the Xenon.

(we shouldn't even talk about how many Itanium's Intel has sold this year- or rather NOT sold this year, compared with their roadmaps of one or two years ago.)

You're right if you think this sounds a bit biased. I've been a real Intel fan boy in my day- heck, I was at their first show and roll out for the 486, which for it's time was a huge leap over the 386 for applications like simulation. Ditto for the Pentium Pro. But Intel has grown lazy, overly optimistic, concdescending, and arrogant over the last few years. The best thing they have going now wasn't even developed in their Santa Clara design center (which I used to be close enough to, that I could throw rocks at it)- the Pentium M is a product of their design group in Haifa, Isreal; and architecturally looks a lot like a marriage between a PIII and an Athlon, with sophisticated clock and functional block power management. Dual core processors with that part will probably be a big part of Intel's desktop and mobile future.

Oh, and speaking of dual core processors; AMD revealed a bit more info about their dual core design at the Microprocessor Forum today, the one they demo'd in HP servers this last September before the Intel Developer Forum; they're 90 nm parts, of course, like the latest Intel parts, using strained silicon and silicon on insulator (unlike the Intel 90 nm parts), and the 205 million transistor dual core processor consumes (drum roll, please) 95 watts running at full song. Can you imagine what a dual Prescott core CPU would run, even at just 2.8 GHz? 150 watts, maybe? 'Course, lets be fair, AMD got a lot of their silicon processing technology from IBM, through their joint development and cross licensing program. IBM has a very good silicon on insulator technology; helps power issues a lot a the finer feature sizes; look where IBM is at with their Power 5 dual core 64 bit processors. That joint development program was just recently re-upped for a few more years... smart move on both their parts, I think.

Gee, that 95 watts for the A64 dual core fits within the original A64 desktop and server power spec. Do you think they planned that all along? Could be, as the existing Athlon 64's have all the hardware for dual core operation, including the hypertransport crossbar switch, except for the second core.... those guys really aren't playing fair, are they? Well, they have a lot of ex Intel guys, so they must be cheating or something....
:B

But bottom line, if you feel a P4 meets your needs better, then by all means get a P4. This isn't religion, ya know, though sometimes folks get a bit carried away with it. Guilty as charged..... :rofl:


~Jon

[brucek]

Thanks Thomas and Jon - great insights, lots to chew on........it'll help while I research this stuff over the next number of months.

Maybe I'll put together a 'Kevin Trouncer'......heheheh

P.S. You'd have to pay me the $250,000 to get me up in that Rutan machine......he'd probably try one of those rolls just for fun.. :E

brucek

[purplepeople]

I am also biased for AMD.

But, that said, I've heard that both Photoshop adn AutoCAD actually take advantage of P4 specific features. And even then, the latest features on the latest chips are too new for the software people to put into their next release... maybe 2 versions from current, but I certainly can't imagine that the coding makes it into the project within a year or so from chip release.

Still, in general, the only reason to buy the latest chips are for the number-crunching power vs 6-12 month old CPUs. The price to do that is about 3 to 4 times the cost of the older CPU at a performance increase of maybe 15%. Which one is better at number crunching? In a study done using a real world 3D model rendered by Accurender, it was discovered that a single Athlon could outperform a dual Xeon system and the HyperThreaded P4s were no match at all. Rendering a fully lit 3D model with raytracing and/or photometrics turned on takes a lot of calculations. It is not unusual for 3 megapixel images to take 12 hours (or more) on a high end workstation. It's a real bummer to come to work in the morning only to realize that a project is delayed by a day just because of a software crash.

So, the old adage is true... you're better off putting your cash into memory and good displays. Like PC3200 memory, RAIDed hard disks or even a very good flat panel. Even the choice of keyboard and mouse are worth than an extra 0.2 GHz of CPU speed. Believe me... I spend at least 9 hours daily in front of these things, not including writing enjoyable posts to various NGs.

If you are doing a lot of Photoshop only, then I should suggest a P4 with at least a 1Gb RAM and striped and mirrored drives is what you should consider to start with. Spend the money on a good CRT (LCDs aren't quite photo quality. Soon, but not yet.) and calibrate the monitor with an Optical Spider. If you can't afford all that, you're better off swapping to an Athlon than give up the RAID array. And let me tell you, a properly calibrated monitor is more than worth any equivalent expense in CPU power.

Considering the amount of trouble I've had with various video cards and their drivers, I suggest waiting until PCI Express has had a chance to get to a second version of motherboards before trying it. Way to much risk for the potential gain.

ensen

[JOY DIVISION]

AMD will lag behind once PCI Express comes to true form. As of now we have not seen it's capabilities yet but hopefully it will catch on.

[JonMarsh]

Here's an interesting article in Cnet regarding AMD's presentations at the Microprocessor Forum conference.

CNET article


The pay off for dual core A64's 90 nm parts apears to be running at the same power consumption as the existing 130 nm parts, (that is, a dual core 90nm consumes the same overall power as a single core Opteron for the sma processor speed), but with a 30-50% improvement in execution speed, depending on the type of program.

~Jon

[Kevin P]

PCI Express is still in its infancy. Only Intel boards are currently available with it, but we should start seeing AMD boards soon. I'd give it a year before it becomes more mainstream, and when it matures enough to actually have an advantage over PCI/AGP.

I went with the Socket 939 Athlon 64 in my new box. It cost a bit more, but I figure for future proofing it was worth it. In a year or two I can drop in a faster chip or a dual-core A64 and really crank up the SETI unit production. This is my first AMD box (I was an Intel guy for years), and so far I'm quite happy with it.

[JOY DIVISION]

Kevin,
With the AMD 64 the heat does not bother you at all like the Athlons before? I'm looking forward to giving them a try since I only tooled with Intel ever since, but I know they are doing better than Intel right now.I have not even looked at their boards yet but Intel boards are running DDR2 with their new boards.

[Kevin P]

Joy,
My A64 3500+ idles at 28C and chugs SETI at 40-44C depending on room temp. No problems with heat here. I did go overboard with the HSF though. The A64s are more efficient than the 32-bit Athlons (in terms of speed per unit of heat dissipated), plus they have the Cool & Quiet feature which lowers idle temps by reducing VCore and clock when the chip is idling.

But then, CPU heat generation is only really an issue with notebooks and silent PC applications. Even a Prescott P4 can be kept comfy with a decent HSF.

[brucek]

I went with the Socket 939 Athlon 64 in my new box

Kevin,

The A8v and the 3500+ combo seems to be very a good choice between price point and future expansion.

I was looking at this combo on a few sites and found it curious most CPU fans seem to only reference the 754 and the 940 socket.

Does the 939 socket require a different fan than the 754 or 940?

brucek

P.S. I wasn't looking at the radiator type - just the regulars...Do you feel the big fans are required on this chip?

[Kevin P]

Brucek,
Any HSF designed for Athlon 64 (K8) will work with Socket 939. The three A64 sockets (754, 940, 939) have the same HSF mounting points. 939 is the newest so the HSF manufacturers haven't updated their compatibility lists yet.

I've heard people having good luck with the stock HSF that comes with the retail A64. Of course if you overclock, or want something quieter you will likely want something bigger. One nice thing about the A64 is it has a built-in heat spreader which makes it easier to get good heat transfer between the HSF and CPU. Apply a thin film of thermal grease, pop the HSF on and tighten it down, and you're good to go.

I only went with the monster HSF in my box for quietness. Small fans run at high RPMs and make lots of noise. My Thermaltake SilentTower runs at 1950 RPM (throttled by Q-Fan) and is quiet and the chip rarely breaks 42C under SETI load.

[brucek]

One of the items in a PC that I find difficult to evaluate is video cards.

I have been looking at GeForce cards lately that might suit me and I have a question for all you guys.

How important is memory size on board the card?

For instance, it seems that there are no end of comparisons and reviews on the net between brands, but I don't seem to be able to get a good comparison of 'like' brands.

Example, in the GeForce FX series. Here's two cards. One costs a bit more than the other. The cheaper card though is an earlier series, but has more memory. How important is that extra memory against a newer card with less memory.

XFX GeForce FX 5700 LE / 256MB DDR / AGP 8X / VGA / DVI / TV Out / Video Card @$191.99

XFX GeForce FX 5900 XT / 128MB DDR / AGP 8X / VGA / DVI / TV Out / Video Card @$273.99

How would you compare these two cards? (I'm sure I can do better on the prices - I include them for reference of price difference) 8O

brucek

[Andrew Pratt]

Bruce i'm sure the guru's will correct me if I'm wrong but from what I've seen the general consensus is that the extra memory doesn't mean beans on the bench scores.

[JOY DIVISION]

Well for now a 128Mb on V/C's will suffice since there are not any games yet out that would require a 256MB, but soon enough there will be.

[JOY DIVISION]

Joy,
My A64 3500+ idles at 28C and chugs SETI at 40-44C depending on room temp. No problems with heat here. I did go overboard with the HSF though. The A64s are more efficient than the 32-bit Athlons (in terms of speed per unit of heat dissipated), plus they have the Cool & Quiet feature which lowers idle temps by reducing VCore and clock when the chip is idling.

But then, CPU heat generation is only really an issue with notebooks and silent PC applications. Even a Prescott P4 can be kept comfy with a decent HSF.

Those are good temps, I was running Swiftech 159r and played around with Doom 3 and Call of Duty and I swear the temps were somewhere around 50-54c. I bet a 28c on idle would be great if you were sneaking for a late night gaming.

[Gordon Moore]

The memory is a red-herring....Joy Division is right....128 MB is all you need for now

http://www.xbitlabs.com/articles/video/display/faq_2.html

The chip doesn’t differ at all, save for its marking (the letters “XT” are written in the top right corner of the protective cover/heatsink). Its recommended operational frequency is 10MHz lower compared to the non-Ultra 5900 chip, 390MHz instead of 400MHz (for notice: the GeForce 5900 Ultra works at 450MHz and the 5950 Ultra works at 475MHz). The 5900XT however clocks the memory at a much lower rate (700MHz against 850MHz of 5900/5900 Ultra and against 950MHz of the 5950 Ultra). This limitation is due to the fact that they use cheap memory chips with a cycle time of 2.8ns (i.e. rated for 714MHz). Besides that, a simpler and cheaper PCB design was specifically developed for the 5900XT – it’s not the NV35/38 reference design. I suppose that these things were made for the graphics card manufacturers to separate sharply 5900XT and 5900-based products.

The 5700LE would be comparable to a ATI 9600
It's a really slow clocked 5700

go for the 5900XT (256 bit card versus 128 bit card should say it all).

[brucek]

go for the 5900XT

Thanks guys. That's good info.

The FAQ referenced by Gordon was very interesting. I hadn't read that one - Thanks.

Specifically, this quote makes me think the 5900XT is a good choice - maybe I'll pull the trigger on that one.... 8)

Here’s your fly in the ointment! Alas, the 5900XT will soon vanish from the product lists of graphics card makers. Such cards were necessary to throw away the remains of NV35 chips and NVIDIA even sacrificed the sales of the GeForce FX 5700 Ultra for a while to get rid of its top-end chips. Now that the 5900XT leaves computer shops, its place will be taken over by the less fast (!) 5700 Ultra and the new GeForce 6800/6800 Ultra GPUs will occupy the hi-end sector. Thus, it’s going to be difficult soon to find a 5900XT graphics card. If you’re still undecided – be quick in making up your mind!

brucek