p4 w/ 800 mhz ram vs Xeon

[joseph alexander]

http://www.anandtech.com/chipsets/showdoc.html?i=1806&p=9

 

"The Pentium 4 features a 64-bit wide FSB interface, and we've already explained the frequencies this FSB can run at. Simple multiplication shows us that the 533MHz FSB can offer a maximum of 4.264GB/s of bandwidth. The 845PE chipset has a 64-bit DDR333 memory interface, offering a maximum of 2.664GB/s of memory bandwidth, and the 850E chipset has a 32-bit PC1066 RDRAM memory interface that provides at most 4.264GB/s of memory bandwidth. As you can see just by looking at the bandwidth numbers, the 850E chipset is perfectly balanced for the amount of bandwidth offered by the 533MHz FSB, which is why it is significantly faster than the 845PE.

 

The 800MHz FSB will offer no less than **6.4GB/s of bandwidth**, which would require either a 32-bit PC1600 RDRAM memory interface (note that the PC1600 standard does not exist) or a 64-bit DDR800 memory interface (also a non-existant memory technology..." (this would be the 800 mhz Rambus that was recently released.. right?)

 

 

From what I understand from this article, the limitation of current day system’s overall performance has been RAM speed. This new platform, that supports 800 mhz RAM, would eliminate Ram as a bottleneck.

 

Are the Xenons intending on supporting this platform?

 

If not, wouldn't the P4 875 or 865 chipset with 800 mhz RAM render faster then an equivalent single Xeon? How much of a difference does the Xeon’s larger cache memory make?

 

A lot of people are telling me that Xeons are grossly overrated and overpriced, and since I need to buy a new workstation, this rambus situation has made the purchase more difficult.

 

Can some one clarify this for me?

 

-Joe

[Greg Hess]

Are the Xenons intending on supporting this platform?

 

Not currently. They will be moving to a 666 (Intel actually rounds up to 667) Front Side Bus Q1 2004. During that time period they may also pickup DC-DDR (Dual Channel DDR) PC2700 to match the increase in bus speed.

 

If not, wouldn't the P4 875 or 865 chipset with 800 mhz RAM render faster then an equivalent single Xeon? How much of a difference does the Xeon’s larger cache memory make?

 

1) Only DP Xeon's have more cache then their Northwood/P4 equivilants.

 

2) If your just comparing a single 3.06 HT P4/800 chip to a single 3.06 HT Xeon/533, of course the Pentium IV will win. Xeon's aren't about single processor performance they're about DUAL.

 

How much will it win by? 5-10% (Theoretical maximum...realistically, 5% or less). All these ram and fsb upgrades aren't really speeding up the machines, their just removing bottlenecks. Kinda of like adding an intake/exhaust to your car. Restores power that was originally being lost.

 

A lot of people are telling me that Xeons are grossly overrated and overpriced, and since I need to buy a new workstation, this rambus situation has made the purchase more difficult.

 

Current Xeon's...

 

1) Use a 533 FSB

2) Use Dual Channel PC2100 DDR.

3) Use the NEW E7505 Chipset.

 

Both the FSB and DC-DDR bandwidth match.

 

4.2 gb/sec and 4.2gb/sec (someone check me if I'm wrong, I can't check the bookmarks to verify, not my machine)

 

Their are also boards available which allow for the use of unbuffered PC2100 DDR, and/or registered PC2100 (if you want greater stability), and are significantly cheaper then previous Rambus Xeon configurations (as well as being faster).

 

Can some one clarify this for me?

 

Dual processor machines are for performance. True performance. Both in workability and effeciency, there is nothing that even comes close.

 

Overpriced? Overexaggerated? Not in the least. When I press render, and it finishes in 10 minutes instead of 25, I can use all that extra time to do whatever the hell I want.

 

And that my friend, is priceless.

[garethace]

You might find some thing informative in my latest batch of Intel related tech news here Greg:

 

http://www.cgarchitect.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=2&t=000153#000008

 

The P4-2.4C with a nice cheap Springdale board should make a useable workstation for many CAD applications at least. How cheap they really are?

 

http://www.newegg.com/app/viewproduct.asp?DEPA=&submit=Go&description=865PE+Neo2%2DS

[Greg Hess]

Here's something to throw a wrench in the latency discussions.

 

If ECC effects latency and performance...why does turning it on on the e7505 chipset...INCREASE performance?

(Tested through render times)

[garethace]

Well at least with the Intel granite bay or canterwood chipset, you have great options to use single or dual channel, ecc or non-ecc.

 

I use ecc rambus dual channel for along time now in a dual 1ghz piii system. i am trilled with the stability of the system for cad work, but try using that system with print resolution RGB renders!!!!

 

No, what i need is a ripping fast DDR memory sub system and plenty of it, with an 800mhz fsb intel chip me thinks.

 

I would love to get back into output and printing/compositing from photoshop again. You have supplying me with alot of very useful know-how in building such a system for rendering/compositing at higher resolutions Greg.

[Richie]

Hello

 

The 850 chip-set is not as good as many believes.

The 2 CPU's MUST share the Total available Memory I/O (while the Athlon can use the whole Memory Bandwith).

 

I hope that is different with the 7505 !?

 

But 200MHz QP FSB Sounds really gooooood (since NLE systems needs this kind of power).

 

Richie

[Mistyk]

Originally posted by Richie:

Hello

 

The 850 chip-set is not as good as many believes.

The 2 CPU's MUST share the Total available Memory I/O (while the Athlon can use the whole Memory Bandwith).

 

I hope that is different with the 7505 !?

 

But 200MHz QP FSB Sounds really gooooood (since NLE systems needs this kind of power).

 

Richie

Hi!

 

The E7505 has shares the memory bandwidth between both CPUs, like the i860 chipset (which I assume you were referring to, as the i850 is a uni-processor chipset).

 

From what I gather there is no significant performance loss inherent in that design, as far as 2-way systems are concerned. Thus the AthlonMPs (not Opterons or Athlon64s) would have an advantage over Xeon DPs, mainly in 4-way (and above) systems, which have been notably absent on the AMD platform. The Opterons may change all this however.

 

AFAIK, the X-way (where X is large) Intel systems have many independant channels of SDR DRAM, so the shared bus limitation should predominantly be present in 2-way Intel system, but as previously stated it's somewhat of a non-issue even there.

 

Please correct me if I'm wrong.

[LivinOnTheEdge]

if your doing mostly 3d modeling/rendering work then 2 cpu's will help alot, because those processes are maxing out the cpu.

 

where as u r only doing graphic design stuff with photoshop, etc. you won't see significant gains from 2 cpu's, cause your mostly using ram.

 

could be worth the money, depending on what u do.