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g4 vs g5
- Thread starter Anarchy99
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The biggest difference is 32-bit (G4) vs 64-bit (G5). At the same frequency, for most operations, using the current OS, they are essentially similar. Code optimization will allow the G5 to do more, but today's apps don't provide a lot of obvious incentive to get the G5. However, I expect Tiger to change that.
Of course, some apps (Photoshop, etc.) use the G5 (and the capability to have 8GB) well already.
Of course, some apps (Photoshop, etc.) use the G5 (and the capability to have 8GB) well already.
Not to mention that the G5 comes wih a frontside bus at half the processors clock speed (or at a third at the lowend version, pretty lousy by Apple).
I think the G4 has a theoretichal upper bus speed at 200 MHz. So even the cheapest G5 has a bus three times faster than any G4 ever can get.
I think the G4 has a theoretichal upper bus speed at 200 MHz. So even the cheapest G5 has a bus three times faster than any G4 ever can get.
For the average low-end user, there honestly isn't a huge difference. A comparitively "slow" 1GHz G4 (or any other processor) will run the applications most people want--web browsing, e-mail, word processing, and some music--just fine. Frankly all the big, beefy computers that companies push so hard to sell don't do anything for the majority of people
Really the only thing that most home users do that will tax a modern computer, unless they like working with video, is playing games. If you don't do that, almost anything will cut it for you.
Even for "prosumer" users, the biggest difference right now with the G5 is the simple fact that even at the bottom end it runs at 1.6GHz, vs 1.5GHz for even the fastest G4. Most people don't need near the 2GB of RAM the G4 can handle, they won't be running any 64-bit applications in the foreseeable future, and the stuff they're doing takes advantage of neither the huge memory bandwidth nor G5 optimizations. The G5 is very fast, but the advantages of its architecture are more for future-proofing and high-end muscle than most users.
As for the future and high-end users, it's been demonstrated that some things run amazingly fast when properly G5 optimized, much faster per-GHz than a G4, and the vast amount of RAM and huge RAM bandwidth can be a huge boost for other high-end tasks as well, so the G5 is going to get more compelling over time.
Really the only thing that most home users do that will tax a modern computer, unless they like working with video, is playing games. If you don't do that, almost anything will cut it for you.
Even for "prosumer" users, the biggest difference right now with the G5 is the simple fact that even at the bottom end it runs at 1.6GHz, vs 1.5GHz for even the fastest G4. Most people don't need near the 2GB of RAM the G4 can handle, they won't be running any 64-bit applications in the foreseeable future, and the stuff they're doing takes advantage of neither the huge memory bandwidth nor G5 optimizations. The G5 is very fast, but the advantages of its architecture are more for future-proofing and high-end muscle than most users.
As for the future and high-end users, it's been demonstrated that some things run amazingly fast when properly G5 optimized, much faster per-GHz than a G4, and the vast amount of RAM and huge RAM bandwidth can be a huge boost for other high-end tasks as well, so the G5 is going to get more compelling over time.
The G4s run on the all powerful 128 bit vectoring unit Altivec Engine, while G5s dont, the G4 is significantly faster per clock speed than the G5, but they dont clock as high as the G5
highest G4 - dual 1.67 ghz (overclocked) = roughly dual 1.8 ghz G5
highest G5 - dual 2.5 ghz (normal) = roughly dual 2.2 ghz G4
highest G4 - dual 1.67 ghz (overclocked) = roughly dual 1.8 ghz G5
highest G5 - dual 2.5 ghz (normal) = roughly dual 2.2 ghz G4
I'm sorry, but you're completely wrong on the first part, and mostly wrong on the second. The numbers you quoted may be correct for Photoshop, but for most heavy lifting the G5 performs MUCH better than that.hjhhjh said:
First of all, the G5 has exactly the same Altivec unit as the G4. It isn't improved any from the G4, but that doesn't make it any slower. If you don't believe me, have a look at Apple's G5 page. The G5 also has a drastically improved floating point unit than the G4, though its integer unit is, if memory serves, the same or a little worse.
Second, I have no idea where you're getting your numbers, but in most real-world tests G5 is at least as fast per clock as the G4. Occasionally it's not quite as fast per clock, and sometimes WAY faster, but on average the G5 comes out well ahead.
Take a look at BareFeats, a respected Mac-centric benchmarking site that runs nothing but real-world tests. If you have a look at this older test or this newer one, you'll note that although in Photoshop the G4 is faster per-clock, in After Effects, FCP, Bryce, and Cinebench, the G5 is far faster than a G4 per clock.
Real numbers:
After Effects: 2.0GHz G5 = a hypothetical 2.36GHz G4
Final Cut Pro: 2GHz G5 = 2.2GHz G4
Cinebench: 2GHz G5 = 3GHz G4 (yes, that much faster)
Bryce: 2GHz G5 = 2.38GHz G4
In Photoshop, the only time the G4 looked good, 2GHz G5 = 1.68GHz G4.
Even in games, when the game is CPU bound (UT2003), the G5 is a hair faster per clock than the G4.
Upgrades?
I do not think that Makosuke was talking about upgrades either, just showing proper links that prove the G5 is faster in most practical cases.
If you have some links proving otherwise, they would be interesting but the major and respectable links for benchmarking and information seem to be showing the G5 having an edge.
I do not think that Makosuke was talking about upgrades either, just showing proper links that prove the G5 is faster in most practical cases.
If you have some links proving otherwise, they would be interesting but the major and respectable links for benchmarking and information seem to be showing the G5 having an edge.
in layman's terms
I have a G4 (500mhz processor with 1gb ram) at home and a G5 with dual 2ghz and 1gb ram at the office. It took over 12 hours for my G4 to export an iMovie project for DVD Studio Pro. The G5 took 25 minutes.
Forget all the techy specs, that to me sounds like the G5 wins hands down!
I have a G4 (500mhz processor with 1gb ram) at home and a G5 with dual 2ghz and 1gb ram at the office. It took over 12 hours for my G4 to export an iMovie project for DVD Studio Pro. The G5 took 25 minutes.
Forget all the techy specs, that to me sounds like the G5 wins hands down!
Nor was I, just the raw power of the G5 chip. As with anything, benchmarks can (an for all practical purposes, should, since a processor is a system, not just a core) be influenced by the system as a whole, but even if you look no farther than the processing core of the G5, it is usually at least comperable per clock to the G4.hjhhjh said:
And though the massive FSB (which is one of the architectural advantages of the G5 that MAKES it fast), cache (which actually isn't that much different), and other subsystems make a difference, that doesn't change the fact that the CORE of the G5 is impressive.hjhhjh said:
Here's why. Basically, even if you ignore all other features and look only at the core, the G5 has exactly the same Altivec vector unit as the G4, can execute an extra instruction per clock, has twice as many floating point units, and a somewhat different integer unit that can be faster or slower depending on the type of calculation.
The individual processing units are as far as you can strip down any processor and still say anything meaningful about it, and the G5 is an impressive beast even on that level. There are low-level benchmarks that bear this out, if you care to look.
The point being that although there are indeed a few situations in which the G4 is indeed faster per clock than the G5, in the majority of situations, both real-world and hypothetical, the G5 is at least equivalent if not significantly faster, and there are identifiable technical reasons for this.
Once you add in the better subsystems that its architecure enables and the real-world advantages of the package you get in a G5 tower, there's no comparison, but even on a purely theoretical level the G5 almost always wins.
So although the G5 may be quicker than the G4, the core itself on the G4 is not obsoleted by the G5 is it?
It seems that although the G5 may be faster, there is still plenty of use to be had from the G4 chip (either faster clocks, dual core??). Am I right assuming this?
It seems that although the G5 may be faster, there is still plenty of use to be had from the G4 chip (either faster clocks, dual core??). Am I right assuming this?
Yes. I for one really don't care for the idea of a G5 laptop when my G4 flies in optimised applications. Coupled with the power equirements, unless they really make Tiger's 64-bit extensions worthwhile, 64-bit (and 8gb) is redundant in a laptop. Bring on dual-core.efoto said:
I know it is expensive however why does the G5 have no 1MB of L2 cache, I mean that prolongs the chips life in a big way.
I have a G3 400MHz with 1MB of L2 cache and it still is fast, and comparing this to a the new 12inch iBook my system still feels more responsive.
once the G5 gets 1MB cache I am jumping in with both feet.
Ram also helps a lot however if you G5 system doesn't support more than 8Gigs of ram you are not using the G5 power in full use.
If only the G4 had 1MB of cache. sad indeed.
I have a G3 400MHz with 1MB of L2 cache and it still is fast, and comparing this to a the new 12inch iBook my system still feels more responsive.
once the G5 gets 1MB cache I am jumping in with both feet.
Ram also helps a lot however if you G5 system doesn't support more than 8Gigs of ram you are not using the G5 power in full use.
If only the G4 had 1MB of cache. sad indeed.
ezkirk said:
You are comparing a single G4 to a dual G5 system.
You are comparing 500MHz to 2GHz.
You are comparing different ram speeds even though its 1Gig.
You are comparing the G5 FSB at 1.0GHz each chip to slower G4.
You are comparing the Graphic Card speed and ram.
You make me laugh.
While you are at that why not compare a G3 400Mhz to a dual G5 2.5GHz system. ROTF
hjhhjh said:
NO.
Dual 1.42Ghz max for the G4.
When you start comparing machines that take A LOT of time, effort and £££ to overclock you can't compare them to to a standard machine.
A dual 1.67Ghz G4 would be tasty though.
m a y a said:
I fully agree. Intel received the message, hence the newer dothan cores at 2mb l2 cache. These chips should be able to remain responsive (depending on your definition) for years to come in comparison to some outdated chips with only 256k or 512k of l2.
If the G4 was changed solely to support 1mb of l2, then placed back in the PB at the same clock rate, I would not hesitate for a moment to pick that system up. I do not know a ton about Mac, I am still learning but in comparison to other systems it seems that the 512k is simply not holding up technology wise
Indeed; just because it's not the fastest processor available doesn't mean it's suddenly useless. I fully expect the G4, especially with some of the most recent improvements, to continue to be useful at the low end and in mobile computers--the power consumption alone makes it very appealing.efoto said:
Kind of silly, true, but his point was that a computer that, looking at processor clock alone, would be 8X faster was in reality 30X faster. Not hugely meaningful, but interesting nonetheless.m a y a said:
I'm not a processor architecture expert, but it's worth keeping in mind that different chip architectures will behave differently relative to cache, so it's at least possible in theory that the "small" L2 of the G5 is due to the way it works, not some kind of cheaping out.m a y a said:
After all, Intel's flagship Itanium 2 super-high-end processor only has 32K L1 and 256K L2 vs the G5's 96K and 512K, and that's certainly not a chip Intel cut any corners on. Even the Power4, the beefy chip the G5 is based on, only has 1.5MB L2 shared between two cores, with no L1, making for only slightly more than the G5.
I wouldn't be surrpised if the 1GHz frontside bus to main memory didn't have something to do with it as well--it's not quite the same thing, but the G5s have main memory running "faster" than even the L3 on the G4.
Again, this isn't to say that more L2 wouldn't make a difference, but it's not a foregone conclusion that it'd be a huge speed boost.
Mostly correct, except that the G4's Altivec unit is supposedly slightly better per clock compared to the G5's. Here's a picture from arstechnica that essentially shows that the G4 can issue two different Altivec instructions per cycle while the G5 can also issue two instructions per cycle but is more limited in the choice of type of instrictions.Makosuke said:
combatcolin said:NO.
Dual 1.42Ghz max for the G4.
When you start comparing machines that take A LOT of time, effort and £££ to overclock you can't compare them to to a standard machine.
A dual 1.67Ghz G4 would be tasty though.
one person on xbench succesfully overclokcked his g4 to a dual 1.67 ghz under MDD look for urself
m a y a said:I know it is expensive however why does the G5 have no 1MB of L2 cache, I mean that prolongs the chips life in a big way.
I have a G3 400MHz with 1MB of L2 cache and it still is fast, and comparing this to a the new 12inch iBook my system still feels more responsive.
once the G5 gets 1MB cache I am jumping in with both feet.
Ram also helps a lot however if you G5 system doesn't support more than 8Gigs of ram you are not using the G5 power in full use.
If only the G4 had 1MB of cache. sad indeed.
The speed difference between your G3 400MHz and iBook has very little to do with L2 cache.
I have been working with Mac's for the last 15 years, and the "most responsive" Mac I have ever used is the 1999 G4 500Mhz single processor.
I have since used Quicksilvers, MirrorDoor, 1st and 2nd generation G5's and apart from the slowness of complex tasks(photshop transfromations, movie encoding and 3D model rendering) the G4 is still the "best: i.e.most responsive" machine our office has had. The difference is the G3 400 is a top range machine, and iBook is a bottom range product. "i" for low poduct range, "Power" for top poduct range. Remember iMac may have a G5 processor but only has 100baseT eternet, where the PowerMac has had 1000baseT since 2000.
Speed on the G5's is also a bit "suspect".
Under energy management you control bus and processor speed. Unless you Perform test with the Processor speed set highest then you only have your 2.5 GHz chips running at 2.0, and it ruins any test. Small note, you can tell when its set to highest by the Hair-Dryer sound comming from you Mac.
When using OSX you must rember that the system is based around"Virtual Memory", which IS NOT RAM but HARD DRIVE. Try booting a G5 From a CD, it takes about 15 Minutes if there is no HD. The computer is limited by Hard Drive Speed now days, not by FSB. Please note HD speed is not ATA100 or ATA133 or SCSI 320, but sustained Write speed which on your average Quicksilver is about 25Mb/s, on a Mirror-door about 32Mb/s and on a New G5 about 37MB/s.
The G4 500 was the last time all components were matched, afterwards you increase processors speed but not ram or bus speeds by the same amount, etc.