# Mac MHz/GHz vs. PC MHz/GHz - how different are they?



## LABachlr (Jul 14, 2004)

I know that Mac's are based on a faster chipset, hence their MHz speed is not the same as the PC MHz speeds.  I was wondering if any of you knew a formula of sorts that would allow you to convert Mac's processors' speeds to PC's speeds and vice versa.


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## Pengu (Jul 14, 2004)

It's nothing to do with chipsets really. It's to do with a) how efficient the processor/bus/memory/graphics/hdd/etc is, and b) how well it works with the software, and how well the software takes advantage of it.

This is what makes the general statement: PPC (used in macs) CPUs are faster mhz-for-mhz than an x86 (used in most pcs). It is to do with everything: processor type (rics vs. cisc) memory bandwidth, memory type, graphics bandwidth, instruction sets, everything. There is no clear way, without doing real-world tests with apps. and even then you have to remember that Apple builds the Macs and the OS, so they can make it work at its best. Microsoft build the OS, and the manufacturers have to supply drivers to make it work the best it can.


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## Zammy-Sam (Jul 14, 2004)

This question is actually based on another: which system is faster. This is a very arguable question. There are applications, that run much faster on macs, eventhough there are some x86-ports available too and of course reversed. Since the systems are uncomparable when it comes to the overall performance, it makes much more sense to reduce the question of performance to a special application.

However, "PCs" doesn't mean there is an Intel cpu installed. AMD actually has a lower clock but runs comparable to faster clocked cpus (take a look at the p-rating). It looks like Intel realized, that it's no more just about clock speeds but - as Pengu said - the combination of cpu, bus, memory, graphic, i/o...


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## LABachlr (Jul 14, 2004)

Valid points.  So, I guess one can't even give a rough estimate as to the equivalent speeds in each platform.  The reason I ask is that I am considering getting a used Powerbook so I can start to fool around with Macs, and was wondering if 500MHz is fast enough in today's world, or at least fast enough to run the latest programs and latest OS at sufficient speeds.  In the PC world, 500MHz wouldn't really cut it.  It'd be doable, but I wouldn't want to deal.  Any advice?


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## Randman (Jul 14, 2004)

Ram makes a big deal. In fact, it many ways ram is as important as mhz. I've read in other places that if you add about 40% to a Mac speed, you get a comparable PC speed, though I'm far from sure how reliable that number is.


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## LABachlr (Jul 14, 2004)

Wow.  If that figure is true in any respect, that surprises me.  I didn't know it would be that high.  If that is the case, that would make the 500MHz system 700MHz, which is OK.  I'd have to see if there were better deals out there first, unless you guys can convince me that a G3 500MHz Powerbook with 640MB of RAM would suffice.


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## tux (Jul 14, 2004)

today my 512mb stick of ram arrived for my ibook g3 700. i installed it and at first wasnt amazed at the speed improvement. then i loaded photoshop and raced it against my pc (athlon xp 2600+ o/ced to 2.2ghz 512mb ram) and my pc only just beat it.

but the powerpc architecture is different then the AMD one. because powerpc are 64bit (i think?) and athlons are 32bit, so in theory i would be running a 1.4ghz g3 if it was a 32bit processor


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## LABachlr (Jul 14, 2004)

LOL.  Very cool.  Good to hear.  I'm assuming that the 512MB stick was all that was in the ibook?  You didn't add to existing RAM?


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## Zammy-Sam (Jul 14, 2004)

tux, there are some details wrong in your post. Your G3 only supports 32bit. The only ppc processor that supports 64bit is the G5. And your theory, that a 64bit cpu is twice as fast as a 32bit is completely wrong. There might be a slight better performance for some memory-intensive application, but the biggest benefit is the ram support for more than 2gb.
However, additional ram does miracles.


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## tux (Jul 14, 2004)

thanks for clearing that up  i asumed that because a cpu was 64bit it did double the instructions per clock cycle then a 32 bit processor  well if my g3 is 32bit then im impressed with its performance 

[edit] LABachlr : i added to the 128mb on the logicboard


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## Zammy-Sam (Jul 14, 2004)

You can find some more info about 64bit processors here.


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## ElDiabloConCaca (Jul 14, 2004)

To directly answer the question about the 500MHz PowerBook, I'd say that if you've got money to burn and don't mind having an outdated machine in a year or two, then go for it.  It'd be a great first step into the world of Macintosh.  You can run the latest OS with the lates software, although it's not going to be blazing fast.  I'm running an older 500MHz machine, and it's getting to be a little long in the tooth.  Sure, it does just fine, but it does leave me wanting more speed.

Be sure to price compare before you buy that PowerBook.  It is an older machine, and much slower than the current new offerings, and will probably leave you wanting more speed.  I think anything over $800 would be asking a little too much, depending on what's included and how much of them (RAM, hard disk, etc.).


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## fbp_ (Jul 14, 2004)

$800!?! wow, I sold my old 500mhz tibook (from the year after the pismo) a while ago for $650 and thought I was ripping the person off...

save your money and buy a modern mac, or if you are unable to then spend what you have now on a pc. there is no good reason to buy a four year old laptop


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## Pengu (Jul 14, 2004)

Hang on a second.

I use brand new PCs at work, with XP Pro, etc, 2.6? ghz P4s, with 256/512 ram, yada yada yada. I still prefer my 4 year old, 400Mhz G4 powermac. it has crashed maybe 3 times since i've been using osx. three crashes in 2+ years. not bad. my work PC usually becomes so unstable, or stuff stops working that i have to restart it (if i am that lucky) before i lose work/time/functionality. I mean. have you ever seen a Windows quicklaunch bar lose all its icons, except not?. The little button effect is still there. but there is no picture and clicking does nothing.

anywho. I would debate the value of a $800 tibook compared to a simmilarly priced new pc..


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## fbp_ (Jul 14, 2004)

work computers tend to be crap regardless though, and as much as I hate to admit it XP is a good operating system, in the year or so I was using it before I tossed my pc I crashed maybe ten times and almost all of that was due to a bad firewire card.

an $800 tibook maybe, but that would be somewhat recent. this guy is asking for advice on whether or not to lay down big money on a pre-tibook pre-g4 pre-osx laptop, and Im saying its crazy. Im not really advocating getting a pc instead, but if its an issue of having a hard limit on price then it would be better spent on a more or less top of the line new pc than a four year old mac, all loyalties aside.


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## mindbend (Jul 14, 2004)

MHZ Myth Sidebar:

I know people are not going to want to hear this, and I know I'll get flamed for it, but for a couple of years I was obssessed with this megzhertz myth and kept a running spreadsheet of dozens of processes run on both Macs and PCs that we used at work.

My conclusion was that, in general, the MHZ is far and away the number one factor in speed. And yes, an 800 MHZ PC was, in general, twice as fast as a 400 MHZ Mac. And, more or less, a G3 was to P3 as a G4 was to P4.

There are a few exceptions where Altivec truly shines (MP3 encoding, some type of video processing) where the Mac was proportionally faster, but inevitably slower just because the PC MHZ was so fast. But again, in general, I found Altivec to account for only 7% speed increase proportionally on average. 

I have not kept up with the data since the G5s hit, so I can't comment on them. 

I did all sorts of tests. 3D renders, Photoshop (dozens of filters and processes), text processing, file processing, I/O file swaps, network performance, etc. 

My data concluded very convincingly that the MHZ myth is not a myth at all, but indeed fact. More or less.

Obviously there are exceptions, as I mentioned above. But a year ago those exceptions didn't mean much, because the speed gap was so huge, it didn't matter if the Mac was proportionally 50% faster, because it was 200% slower in actual MHZ netting -150%. And of course you can skew the data by starving a box for RAM or using slow drives or an outdated ethernet card, etc. But, IN GENERAL [he says one more time], similar machines performed proportional to their MHZ. Now I suspect that the G5 may change that a bit given its amazing architecture and solid chip. From what I've seen playing around at the store, the thing is just freaking fast. It seems to perform about 30% greater proportionally to a PC MHZ rating. That's just my semi-educated guess after comparing some charts and such.

Fortunately, those days [of slow Macs and huge speed gaps] are over. The speed gap has closed or narrowed to the point where it's not a big separation. I don't keep track of the data anymore because I love and prefer my Mac for reasons beyond pure horsepower. And when I grab a G5 this fall, I guess it will be the best of both worlds.


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## Pengu (Jul 21, 2004)

So why then do AMD sell their CPUs based on a speed rating not a mhz value, and why are Intel now moving to the same type of marketing? because Mhz really doesn't mean everything.


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## Zammy-Sam (Jul 21, 2004)

I agree to Pengu and disagree to mindbend as well.
MHz means a lot when comparing processors using very similar or same architectures such as P4 2Ghz vs. P4 3Ghz or G4 500 vs. G4 700 (not considering other components such as memory, graphic unit, bus... which are actually as important as the cpu when looking at the overall performance)
But when it comes to the comparison between different architectures such as G4 vs P4 vs Athlon XP, the Mhz/Ghz doesn't in fact mean much.


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## Ailes Grise (Jul 21, 2004)

I got myself a new 12" 867 PB w/640 Mb Ram about a year ago to get into Macs. 
While I did not get the PB to do graphics work, I started to compare the PB
with my P4 1.5, Quadro equipped PC. To be honest, I can't tell the difference
for most tasks. 

Only when I tried to run Maya did the powerbook struggled
and renderings were very slow. But I realized then that I really liked working 
with Macs, so when time came to replace the PC, I ditched the plan to get a DP Xeon
machine and bought a DP 2Ghz G5 instead and switched my Maya licence to OS X, much to the surprise of my peers. 

I switched to Macs also for reasons beyond processor speed, and I think you
don't really need a 3Ghz machine if all you'll be doing is surfing or wordprocessing,
but I have to admit that the arrival of the faster G5's did play a role when deciding
to change my 3D workflow to Macs.


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## LABachlr (Jul 21, 2004)

Well, there certainly seem to be differing opinions on the subject.  However, based on the overall consensus, more or less, I think I am going to opt to spring for a current model.  I am all about speed, which is quite evident seeing I am about to spend $200 just so I can upgrade my laptop's HD from a 30GB 4200RPM 2MB cache hard drive to a 60GB 7200RPM 8MB cache hard drive.  I just can't deal with slowness.

Also, I am now thinking of using the Mac to render video, and will need it to keep up with my PC setup to justify getting it.  Originally, I just wanted to get a Mac so I could start fooling around with it and learn today's Mac's (I used to work on Mac's, but that was a while ago; switched to PC's on account of a larger clientele base).  But I am now thinking that a new Mac would be a great asset to my businesses.

Btw, Pengu, with regards to your brand new PC's at work giving you hassle, that is not normal behavior of PC's if they are maintained/protected.  Don't base all PC's on one PC.  I have had this PC for almost two years with zero crashes.  However, I maintain it and protect it.  Your problem with your work PC could be on account of either spyware or viruses.  Most likely, it could be a virus.

Make sure that your PC at work is running an anti-virus program, that its virus definitions are up-to-date, and that it is set on auto-protect.  Also, you might try downloading and installing Ad-aware and Spybot, and running them to scan your work's PC for spyware, malware, etc.  If your work PC does not have an anti-virus program running, then get AVG Anti-Virus.  

All of those programs are free.  AVG has a free edition that is for non-commercial use, but you could use it just to see if your system has a virus.  Or, you can download AVG's Pro version and use its 30 day trial period.

But, either way, it is imperative that a PC be maintained by protecting it from viruses and spyware, as PC's are targets for most, if not all malicious scripts.

Gotta love having a Mac just for that fact alone.


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## mindbend (Jul 21, 2004)

LABachlr,

I went to the local Mac store a few weeks ago and ran some tests in Photoshop and Final Cut, among other things. 

It was a Dual 2 GHZ with only 1 GIG RAM.

On a couple hundred MB Photoshop file, the G5 was quite snappy, but you could tell it was hitting the hard drive on occasion. Presumably more RAM would really make that thing shine. Overall, very solid. I'm used to working on multi-gigabyte files, so it takes a lot to impress me in Photoshop.

Final Cut on the other hand was just wicked fast. I was getting several tracks of video and titles, each with filters, transitions and motion with NO RENDERING required. Now, keep in mind, that's just DV proxy mode no rendering, but that's pretty much how we all edit anyway. I could realistically say that many of my video projects could be fully edited without ever rendering until the end stage. Certainly 90% of most any project would be render-free. HUGE production efficiencies. Keep in mind, this is without Apple's new CoreVideo, which presumably will open this up ever farther.

For more compelling evidence of OS X's/Mac's power in video:

http://www.apple.com/motion/video/
http://www.apple.com/finalcutpro/video/


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## mi5moav (Jul 21, 2004)

I really think that at this point on hte grand scheme of things the lowest one should go would be an 800mhz G4/G3


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## LABachlr (Jul 21, 2004)

Cool.  Thanks for the info, guys.


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## LABachlr (Jul 21, 2004)

Btw, mindbend, that is pretty impressive.


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## Pengu (Jul 22, 2004)

Um. in regard to the PCs at work not being "maintained". I work in the IT Services department. the thing had winxp reinstalled maybe.. 5 months ago at the most. and not it does not have spyware/viruses.


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