Pentium 4 pros and cons

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Originally posted by Arcadian:
My one comment about you post is concerning the last paragraph. I don't believe the cache will ever transfer less than 256 bits of data. The reason being is that the Pentium 4 uses 128 byte cachelines, and will always transfer that amount of data. Using a 256 bit datapath, that means it takes 4 ticks of the 1.5GHz Pentium 4 clock to transfer the cacheline, and it should always take that long. In this case, the 256 bit wide datapath is a completely necessary addition.

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Thank's for the information on that. I guess I still have some confusion in that area and need to read a little more about it.

Hi - out of 50+ posts only one (mordilin(sp) has even mentioned x87 performance. While all the marketing departments in AMD/Intel talk about mmx, 3d-now, sse, and now sse-2, still after 3+ years 95 percent of all games and 3d-workstation apps use x87 (not SIMD). No x87 is not "sexy"? like SIMD, but at least its used in current on the shelf software - why even buy a chip that will run sofware (that MIGHT be optimized in two years), whan by then siad chip will be opsolete (or useless if software does'nt end up optimised for sse, sse-2 etc.....). x87 is not ONLY used "workstation" type software! This used in everthing that uses the fpu. In the early 90's games were integer based (i.e. Doom), after Quake (in 1995) virtually all 3d-games use x87 (not SSE (only Quake-3 as extention, still basic engine is x87!). the p-4 in every benchmark shows truely k-6 (and winchip-2) levels of x87 (comparing to same clock). This is 1/2 the speed of the Athlon (k-7). So, a k7 - 700 mhz will run Quake-1,2, Unreal, etc... at same same as a p-4 1400 mhz!. Until SSE is actually used, (if ever), there is no incentive in my mind to buy this thing. BTW CAD is integer based (if 2d), only 3d stuff uses the fpu. 3d-studio will run faster on a k7 due to fpu. True, high bandwidth is a help - but only so far, the p-4's x87 is truely poor and no amount of bandwidth will make it better. The rest of the chip looks fine to me, but without a good fpu, i'll have no use for it.
I'm not an EE, and no flames please - no disrespect, no ranting intended, just a reminder that x87 is like x86 - a foundation.

To my understanding the FPU on the P4 should be better than that of the PIII, possibly even exceeding the Athlon (which most people, myself included, consider as the current FPU leader). I think the FPU has gotten a lot of knocks because people got a hold of benchmarks run on A0 Si, which I believe had a screwed up FPU.

We'll find out for sure on Monday, but I expect Quake III performance to blow away a 1.2 GHz Athlon on a DDR system. I wouldn't be surprised at more than 200 fps.

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Originally posted by Marsolin:
To my understanding the FPU on the P4 should be better than that of the PIII, possibly even exceeding the Athlon (which most people, myself included, consider as the current FPU leader). I think the FPU has gotten a lot of knocks because people got a hold of benchmarks run on A0 Si, which I believe had a screwed up FPU.

We'll find out for sure on Monday, but I expect Quake III performance to blow away a 1.2 GHz Athlon on a DDR system. I wouldn't be surprised at more than 200 fps.

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Yes Quake-3 will run faster due to sse extensions, but the other current 500+ game titles will run slower - as well as rendering programs like 3d-max, lightwave. The p-4 will run streaming apps like mpeg1,2, & 4 better than the p-3, and k-7 due to sse patches. But the vast majority of apps will are not sse and will run slower. I've got around 5 flight sims - ef2000, janes f-15, janes ww2, flying corps, and european air war NONE of these titles have mmx, sse, or 3d-now. All of them get their frame rates from the x87 fpu only!. And EAW, WW2 will give you about 40 fps on a 1-gig p-3, so you need all the x87 speed you can get esp. with 100+ bombers, flack, villages, trains, and low altitude!. As far as I know only FPS (first person shooters (and only a few at that)) have sse, 3d-now patches - I've looked for them for my sims, there aren't any. http://dev.www.sharkyforums.forums.relay.cool/.

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Originally posted by gaffo:
Yes Quake-3 will run faster due to sse extensions, but the other current 500+ game titles will run slower - as well as rendering programs like 3d-max, lightwave. The p-4 will run streaming apps like mpeg1,2, & 4 better than the p-3, and k-7 due to sse patches. But the vast majority of apps will are not sse and will run slower. I've got around 5 flight sims - ef2000, janes f-15, janes ww2, flying corps, and european air war NONE of these titles have mmx, sse, or 3d-now. All of them get their frame rates from the x87 fpu only!. And EAW, WW2 will give you about 40 fps on a 1-gig p-3, so you need all the x87 speed you can get esp. with 100+ bombers, flack, villages, trains, and low altitude!. As far as I know only FPS (first person shooters (and only a few at that)) have sse, 3d-now patches - I've looked for them for my sims, there aren't any. http://dev.www.sharkyforums.forums.relay.cool/.

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Yeah... I have the feeling Pentium 4 will be a tough sell for Intel in the beginning. I believe they will have to rely on software improvements over time, while they work on hardware tweaking, and gaining megahertz. It looks like Pentium 4 will follow the path of the Pentium Pro in the respect that it will have little improvement in the beginning, but will be able to grow as Intel adds more value through the life of the processor. I believe Sapasion is right: Northwood with DDR will be the better choice for an upgrade, and that won't be available until the second half of 2001. I'm sure Intel will be able to make money with the Pentium 4 due to brand name recognition, but it seems that it will have little value over the Pentium III to begin with. My opinion only. https://www.sharkyforums.com/images/.../2005/06/5.gif

I agree, once the .13 micron is out then a weak x87 at 3ghz is still fast. I have nothing against "progress" and sse, 3d-now etc.. is fine by me. But I just don't see much support for them in my average software collection (most dating from mid-late 90's). It's just maddening to me to know the p-3 has two-piplined (1.5?) x87 units, the k-7 has three, and then the "newest-most advanced" chip has one! I know sse is projected to be the future, and thats fine, but why at the expense of x87. Seems to me at the very least the p-4 could have inherited the p-3's x87 and just added the sse2 feature set. The pentMMx had same fpu performance as classic, the p-3 had same as p-2 and added sse. SSE2 should not be acquired through paying a price, but added to current expected performance. I just hope the simple p-3 (the .13 micron one) is'nt going to go the way of the k-6's. Where the one I'd like to buy in a year ends up being phased out from the desktop and only offered for mobile! Last year I waited and waited and waited for a 600 mhz k-6+ to upgrade my winchip, but only the mobile ones were offered in retail - so my socket seven became a total deadend and not really worth upgrading to a 400 mhz k-6-3 http://dev.www.sharkyforums.forums.relay.cool/ hope p-3 will still be around after the p-4 blitz. Hell a little ATX-flex case with the up-and-coming integrated G-force videocard and 1.2 ghz p-3 with DDR (maybe ALi's?-don't like Via's memory performance) could prob. be had for 300-bucks in a year.

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Originally posted by gaffo:
I agree, once the .13 micron is out then a weak x87 at 3ghz is still fast. I have nothing against "progress" and sse, 3d-now etc.. is fine by me. But I just don't see much support for them in my average software collection (most dating from mid-late 90's). It's just maddening to me to know the p-3 has two-piplined (1.5?) x87 units, the k-7 has three, and then the "newest-most advanced" chip has one! I know sse is projected to be the future, and thats fine, but why at the expense of x87. Seems to me at the very least the p-4 could have inherited the p-3's x87 and just added the sse2 feature set. The pentMMx had same fpu performance as classic, the p-3 had same as p-2 and added sse. SSE2 should not be acquired through paying a price, but added to current expected performance. I just hope the simple p-3 (the .13 micron one) is'nt going to go the way of the k-6's. Where the one I'd like to buy in a year ends up being phased out from the desktop and only offered for mobile! Last year I waited and waited and waited for a 600 mhz k-6+ to upgrade my winchip, but only the mobile ones were offered in retail - so my socket seven became a total deadend and not really worth upgrading to a 400 mhz k-6-3 http://dev.www.sharkyforums.forums.relay.cool/ hope p-3 will still be around after the p-4 blitz. Hell a little ATX-flex case with the up-and-coming integrated G-force videocard and 1.2 ghz p-3 with DDR (maybe ALi's?-don't like Via's memory performance) could prob. be had for 300-bucks in a year.

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You seem to think that the Pentium 4 has poor x87 performance, but I think you're wrong. I believe the Pentium 4 has superior floating pointer performance compared to the Athlon, even without SSE. The only problem is it will likely need software optimizations to make the most use out of it. You see, the Athlon could also use optimizations, as can be seen in the new DirectX 8, which uses Athlon floating point optimizations in the T&L engine.

The Pentium 4 could also use optimizations. The Athlon may have 3-way superscalar floating point, but when you think of it, the Pentium 4 has 4-way. It's actually 2 superscalar pipelines, but they are both double pumped, which gives an effect of a 4-way engine. For optimized programs, the Pentium 4 should perform better.

One way of optimizing for this is to align data at certain memory addresses so that the data variables are more likely to be in cache. Another way is to group floating point arithmetic in sets such that they can make the most use of the superscalar pipelines. Yet another way is to try and reduce complex math into simpler instructions in order to streamline the Pentium 4 pipeline. In other words, instead of using cos or sin instructions, use optimized routines made from adds and shifts (which is usually included in most modern libraries).

There are many ways that have been found to optimize around Pentium III architecture, and I'm sure that soon enough, there will be great optimizations around the Pentium 4 architecture. The unfortunate thing is that it will likely take a while, and we may not see drastic improvements in current software.

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Originally posted by Arcadian:
You seem to think that the Pentium 4 has poor x87 performance, but I think you're wrong. I believe the Pentium 4 has superior floating pointer performance compared to the Athlon, even without SSE. The only problem is it will likely need software optimizations to make the most use out of it. You see, the Athlon could also use optimizations, as can be seen in the new DirectX 8, which uses Athlon floating point optimizations in the T&L engine.

The Pentium 4 could also use optimizations. The Athlon may have 3-way superscalar floating point, but when you think of it, the Pentium 4 has 4-way. It's actually 2 superscalar pipelines, but they are both double pumped, which gives an effect of a 4-way engine. For optimized programs, the Pentium 4 should perform better.

One way of optimizing for this is to align data at certain memory addresses so that the data variables are more likely to be in cache. Another way is to group floating point arithmetic in sets such that they can make the most use of the superscalar pipelines. Yet another way is to try and reduce complex math into simpler instructions in order to streamline the Pentium 4 pipeline. In other words, instead of using cos or sin instructions, use optimized routines made from adds and shifts (which is usually included in most modern libraries).

There are many ways that have been found to optimize around Pentium III architecture, and I'm sure that soon enough, there will be great optimizations around the Pentium 4 architecture. The unfortunate thing is that it will likely take a while, and we may not see drastic improvements in current software.

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Don't know what you mean by "double pumped" but from what I read only the ALU will be double pumped.
Data aligning is nothing one need to worry about either, all compilers does this for you. You have to specify it specifically if you want it the other way (for example when loading fileheaders into a struct). My guess is that in about 99% of the cases the software on he market today has close to all of it's data aligned in almost all situations. So, the P4 has nothing to gain from such things 'future optimizations' in this area.
Btw, the best way to do sin/cos is to use lookuptables. A couple of kb memory is all it takes to get enough precision for most cases.

This discussion is what got me into the forums in the first place. I would just like to say kudos to Arcadian for starting some of the most interesting and informative discussions I have seen.

Also, I would like to thank all of you who have contributed to the discussion.

Danke https://www.sharkyforums.com/images/.../2005/06/5.gif

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Think outside the box or be forced to live in one.

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Originally posted by James:
This discussion is what got me into the forums in the first place. I would just like to say kudos to Arcadian for starting some of the most interesting and informative discussions I have seen.

Also, I would like to thank all of you who have contributed to the discussion.

Danke https://www.sharkyforums.com/images/.../2005/06/5.gif

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Hey, thanks for the complement! https://www.sharkyforums.com/images/.../2005/06/5.gif

It really means a lot that people are enjoying my posts. I even notice my topics are appearing a lot in the Sharky Forum Spotlight articles on the main page. Pretty cool... I guess I'm making a name for myself. https://www.sharkyforums.com/images/.../2005/08/2.gif

I've been trying to think of another good topic recently, and I have a couple ideas I may post tomorrow or Monday. Also, feel free to start a topic of your own if there is an area you want to talk about. You don't even need to know much about it... just throw a few questions out, and I'm sure some of us will take off with it.

A lot of the benchmarks you see are memory bandwidth dependant - specfp2000 is half memory and half fpu. whatever happened to benchmarks that stress fpu only (with the 1-cache). I'm thinking were gonna see more fpu benchmark FUD here soon. JC's site has a lot of non-bandwidth-ram benches. A guy named Tim Wilkins has two-three of them. A relavent site is http://www.tech-report.com/news_reply.x/1519/ --- a benchmark called molecular dynamics is used and all data fits into 1-cache and fpu (so memory bandwith is irrelavant - therefore each chips fpu alone is stressed - a a fair comparison possible). The athlon beats p-4 two to one.

There's been a lot of talk about the lack of MMX/SIMD software on this thread so I thought that I'd add my 2 cents.

The reason there are so few apps that use mmx or simd is that you have to program in assembler in order to use mmx or simd. The excetion to this is the Intel compiler that provides mmx/simd primitives in C/C++ but hardly anyone uses Intel's compiler. What's more, Microsoft has been a huge slacker concerning simd. They only recently added inline assembler support for simd.

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Originally posted by zephyr:
There's been a lot of talk about the lack of MMX/SIMD software on this thread so I thought that I'd add my 2 cents.

The reason there are so few apps that use mmx or simd is that you have to program in assembler in order to use mmx or simd. The excetion to this is the Intel compiler that provides mmx/simd primitives in C/C++ but hardly anyone uses Intel's compiler. What's more, Microsoft has been a huge slacker concerning simd. They only recently added inline assembler support for simd.

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It was my understanding that Microsoft's VC++ has MMX built into it, and that SIMD (if it isn't already there) will be added soon. Usually, Intel's compiler enhansements filter down to Microsoft's compilers as well. In addition, I believe there are a lot more developers than you may think that use Intel's compilers.

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Originally posted by Arcadian:
It was my understanding that Microsoft's VC++ has MMX built into it, and that SIMD (if it isn't already there) will be added soon. Usually, Intel's compiler enhansements filter down to Microsoft's compilers as well. In addition, I believe there are a lot more developers than you may think that use Intel's compilers.

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MSVC has support for MMX in inline assembler but does not generate MMX code itself. To get inline assembler support for 3dnow and sse you need to download and install msvc service pack 4 (126MB) and also a special processor pack.

Arcadian - i was right! the x87 is poor. Go to acehardware and see the finest reveiw yet! x87 is still the fpu standard - MDK-2, microstation, povray - all show the p-4 at 60-percent speed of k-7 https://www.sharkyforums.com/images/.../2005/06/5.gif. They say racing games and flight sims are not x87 based - racing may be true, but flight sims have no sse support. Only video encoding and quake-3 performed well - and mostly due to suppoir memory, not sse. When DDR-333-400 mhz come out the k-7 will win all benchmarks.

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Originally posted by gaffo:
Arcadian - i was right! the x87 is poor. Go to acehardware and see the finest reveiw yet! x87 is still the fpu standard - MDK-2, microstation, povray - all show the p-4 at 60-percent speed of k-7 https://www.sharkyforums.com/images/.../2005/06/5.gif. They say racing games and flight sims are not x87 based - racing may be true, but flight sims have no sse support. Only video encoding and quake-3 performed well - and mostly due to suppoir memory, not sse. When DDR-333-400 mhz come out the k-7 will win all benchmarks.

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Yes, Gaffo. I will admit that your prediction ended up prooving more true. Without optimizations, the Pentium 4 floating point does seem pretty poor. However, if SPECfp2000 is any indicator of how the Pentium 4 will perform with SSE/SSE-2 enhansements, then I think we can see pretty dramatic score increases. Not like the 5% that MMX gave, but rather som serious 20%-30% improvements. So the jury is still out on the Pentium 4 floating point, except that the x87 without optimization does indeed underperform.

Arcadian (or anyone else ofcourse)

I'm very interested in learning more about the discussed subject and other technology related subjects.

You seem to be very well informed, can you point me to resources on the net were I can learn more?

Thanx

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'There are no stupid questions, only stupid answers'

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Originally posted by Angelus:
Arcadian (or anyone else ofcourse)

I'm very interested in learning more about the discussed subject and other technology related subjects.

You seem to be very well informed, can you point me to resources on the net were I can learn more?

Thanx

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Well, the first place I'd recommend is right here. https://www.sharkyforums.com/images/.../2005/06/5.gif

You can learn a lot by speaking to others who have experience in the field. There are other forums I'd recommend as well, including the general forums on www.aceshardware.com .

I would also recommend a web page by Paul DeMone called www.realworldtech.com .

However, you must remember that most of the opinions out there are just opinions. Don't believe everything you read, because a lot of it is FUD (Fear, Uncertainty, Doubt). Try to get a general idea from a lot of people's opinions, and then you can form some of your own. Good luck, and if you have any questions, feel free to post in this Highly Technical Forum here, and I'll be sure to read it. https://www.sharkyforums.com/images/.../2005/06/5.gif

P4. Pffft! Yea right, like anybody will buy those!

:D

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Originally Posted by Spank_Me_Hard

P4. Pffft! Yea right, like anybody will buy those!

:D

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What could possibly posses you to dig up this relic of a thread?

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Originally Posted by Geforce255

What could possibly posses you to dig up this relic of a thread?

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It was mentioned in the off topic thread about the greatest moments in Sharky Forums history.