PIII733 vs PIII750

[Guest]

According to intels own benchmarks the PIII733 outperforms the 750 in every area. Am I the only one who fins this a bit bizarre (as I have just ordered a 750).

Anybody know if this is correct and if so, why?

 

[ledzepp98]

i don't know if it is true since i haven't seen head to head benchmarks but it seems reasonable. if you think about it, the 733 has a 133mhz bus speed and can take advantage of pc133 ram. the 750 has only a 100mhz bus speed and can only take advantage of pc100 ram (it can use pc133 but it will only run it at 100mhz). i think that this will overcome the 17mhz defecit of the 733.

 

[Guest]

I'd have thought that benchmarks would be performed on identical systems (i.e. containing PC100 RAM). Otherwise, they are not exactly valid.

Anyway, i'm currently only using PC100 so it's OK.

 

[Sojourn]

that's the whole difference between the 733 and 750. One has a 133MHz FSB at a 5.5 clock multiplier, and one has a 100MHz FSB at a 7.5 clock multiplier. The memory runs at the same clock as the FSB. The 33% extra memory bandwidth and lower memory latency gives a bigger performance boost than the 3% increase in CPU clock speed.

/Athlon-1.2GHz@1370MHz(137MHz*10)/Asus_A7V133/<P ID="edit"><FONT SIZE=-1><EM>Edited by Sojourn on 03/29/01 11:07 AM.</EM></FONT></P>

 

[Crashman]

To make the system identicle they would have to use PC133, clocked at 100 for the 750 and 133 for the 733.

Suicide is painless...........

 

[Grizely1]

Not at all bizarre. The 733 has a 133MHz FSB, whereas the 750 has only 100MHz.

-----------------
"648kb is all the space anyone will ever need!"

Bill Gates, 1980s

 

[Guest]

At nominal settings, the PIII733 surpasses the PIII750 because of the fact (all ready made abundantly clear, above) that the memory bandwidth of the 733 has a 33% advantage over that of the 750 chip. The extra 750-733=17MHz yields a trivial 2.3% processor speed advantage.. FAR outweighed by the better memory performance. This illustrates the value of memory bandwidth.

The ASUS A7M-266 (one example..more info, see sharkyextreme) supports the dual-datarate 133x2=266 DRAM memory that has been use in other applications like the the GeForce video cards for some time now. This motherboard allows a 166% increase (latency problems should be solved soon with DDRII memory) over PC100 memory at nominal settings. The board is made for Socket A CPUs, which have additional advantages.

P4 systems have 400MHz memory bandwidth, and the sharyextreme crew has gotten 600MHz out of an ASUS P4 board with complete stability (check it out).

Other slot/socket A boards have been at 200MHz sytem clock for a while now (ASUS A7V, for example).

BUT READ THIS!!!!!
That being said.. the PIII750 might actually be faster than the 733 when overclocked. Here's why:
If your 750 posts with a system clock setting of 110MHz, it'll actually post 7.5x110=825MHz. At 120MHz FSB, that post will show up at 7.5x120=900MHz. Many motherboards are near the top at 133MHz, so the 733 chip can't benefit that much going from 133 to 140, for example (if the motherboard will run at 140). Most BX boards with accomodation for overclocking the system clock ARE STABLE at many settings above 100.

Now, you would have to bench mark these settings to document the performance. If you don't overclock, buy the 733, but if you want to go faster.. strap a decent Heat Sink/Fan onto that 750, increase the voltage to 1.95V, and set the system clock at 133.. It'll post 7.5x133=998MHz, WITH 133MHz FSB !!

I can assure you..that'll beat the 733.

 

[Guest]

To bad he already got the PIII-750, heh.

 

[Crashman]

Yeh really, it's hard to get a 750 to run stabley at 1GHz. Much easier to get a 700 to run stabley at 933. Much lower voltages and lower heat.

Suicide is painless...........

 

[Guest]

Unless you are running intensive database searching programs, doing frequent complex graphics transforms, or crunching large energy minimization calculations for molecular modelling, the 750 will be more than satisfactory at nominal settings.

But, you need to keep in mind that the TALL internal multiplier can give that CPU some legs, even if you have 'only' retail boxed CPU/FAN (actually, a damn good package). You would be well advised to dig into your motherboard documentation for some overclocked system settings. Even if your MB can only offer a couple of moderate OC settings, they might make tangible differences for you if your really need performance. You didn't specify your MB brand/model, and you didn't tell us who made your RAM, or what speed it is.

Not that the rating is a 'limit'.... I have CAS3 PC100 RAM from thechipmerchant posting with system clock at 133 to allow my PIII 600E to run at 6x133=800MHz !!! It is completely stable. Completely stable with TWO SCSI cards (one is an old ISA adaptec 16bit card!), network, modem, sound. The amazing thing is that it's a flip chip in a generic CPU slotket card that offers no core voltage options !!

Look for at least 110MHz system clock (FSB). In fact, realistically, you should have NO PROBLEM getting to 120FSB. This is moderate overclocking for BX, and unless you have a real dog for a motherboard, or managed to get stuck with exceptionally low quality ram, you should be able to tap some of that potential in the 750 (crashman is right about the 700.. I have one in this gamer/browser turning 140MHz FSB into a 980 post.. at 1.65V core, with a cheap golden ORB absolutely stable, with certification).

But the wusy is ALL WRONG saying 'should have gotten the 733". He obviously has not BX/PIII experience.

Do it.

Clonan the Cyberian

 

[Guest]

OK wusy, you own a BX board and have lots of experience, but that does not excuse you from giving him the incomplete advice to buy an EB series CPU instead of an E CPU, because you say it is 'faster'. And if you look carefully at my previous post, you will see that it clearly advises that he buy the 733 if he does not plan to overclock.

There are at least three reasons why the 100MHz version is better for BX (as well as VIA Apollo 133A, Intel 810, Intel 815, and others) and most other motherboards that give you the 2/3x multiplier for AGP, have a mechanism for core voltage adjustment, and support slot 1 or S370..

#1, the taller internal multiplier gives the E series substantially more overclocking range, and if the 2/3x AGP multiplier is present (it is available on all of the above mention chipsets), your graphics will get a boost as well.

#2, the taller internal multiplier gives the E series substantially more overclocking range, and if the 2/3x AGP multiplier is present (it is available on all of the above mention chipsets), your graphics will get a boost as well.

#3, the taller internal multiplier gives the E series substantially more overclocking range, and if the 2/3x AGP multiplier is present (it is available on all of the above mention chipsets), your graphics will get a boost as well.

Again, I specifically said in my previous post that if he does not plan to overclock, buy the 733. I guess you missed that.

But if Todders is willing to read articles like Tom's describing BX running 133MHz (last Spring, as I recall), and have the manual for your motherboard, you would be a dope to waste money on the 733 version.

I'm just trying to make it clear for Todders that the 750 (or better yet, as crashman mentioned.. the 700E) has more potential, period. Sorry I snubbed you in the process, but he needs better, more complete advice to make a good decision. Your comment recommending the 733 sounded final and uninformed.

<P ID="edit"><FONT SIZE=-1><EM>Edited by clonan on 03/31/01 09:46 AM.</EM></FONT></P>