[Cathar]

Originally posted by joemac
According to Intel spec sheets:
To allow for the optimal operation of Intel processor based system the thermal solution should be design so that the temperatures remain within the minimum and maximum case temperature specifications (Tc). Intel defines the case temperature at the geometric top center of the processor I.H.S.
Removing the I.H.S will pretty much void all of Intel thermal spec’s as they are based on using the I.H.S. I don’t know but even I would hesitate on removing my I.H.S on my new CPU that I just spend $500 + just to say – look it’s more like a die sim now.

ftp://download.intel.com/design/Pent...s/29864310.pdf

Problem is, Tc is just an arbitrary test temperature, and nothing actually reports it. It is of use to a test setup whereby a channel has been cut into the IHS or heatsink to place a thermocouple in that location. The temperatures that the P4 reports is not Tc.

There's nothing wrong with using a die simulator which includes an extra IHS style device to test waterblock performance for IHS scenarios, and this would indeed be desirable as to date I'm not aware of a single publically visible testbed which has ever done this.


Winewood - addressing your questions:

Why would anyone test a cascade on a p4 setup?

I believe that the question actually applies to most any cooling device, not just the Cascade in particular. Why would anyone test a cooling device on a P4 with it reporting temperatures in the way that it does? At the very least, one would require a Tc style setup as described above to get the beginnings of a semi-accurate P4 test scenario if one truly wanted to determine what is going on with a P4.

AND if the testbench using a diesim w/out IHS cant replicate a IHS which is the new environment, how can anyone test the cascade?

Well, an IHS is just a 1.5mm thick piece of copper sitting atop a die. It really isn't that hard to grab a 1.5mm thick piece of material and stick it atop one's bare-die simulator, and then use that to predict the performance of a cooling device in an IHS scenario. Again, such issues are not restricted to the Cascade, it's just that the Cascade exercises a flaw in the way in which P4's calculate and report their temperatures.

The overclock would vary with each mobo, northbridge, memory etc....

This is true. However, the stability a particular overclock on any given motherboard/CPU/setup tends to be very closely tied to the peak die temperature of the CPU. One cannot predict if something will overclock better, but one can predict the range of water temperatures (affected by ambient temperature presumably) over which a particular overclock will remain stable. People like to overclock in summer just as well as they can overclock in winter. If a waterblock is able to better provide a stable summer overclock, then that can be just as desirable as, and probably more so than, a waterblock that reports xC lower temperatures.

How do we know the cascade is suitable for use with an IHS as a blanket statement? How can we tell ANY block is good for an IHS as any kind of statement?

Quite correct. How do we know that anything is suitable for use with an IHS as a blanket statement? We don't. We look to people's experiences usually to find out.

So, without this accurate testing, how was anyone able to come up with "2C under the white water" as a statement? Was that just on an AMD tbird?

Well, the actual statement that I always quoted was something like this:

"The reference Cascade performed very close to 2C better than my reference White Water on a T'Bred B & Barton CPUs. The motherboard used was an Abit NF7-S Rev2.0. The CPU's were run at 2.4GHz/1.90v, using BurnK7 as a CPU load program, and on my setup"

Others tended to summarise that down to an over-simplification of "the Cascade is 2C better than the White Water".

Truth of the matter is that it's not that simple. People's experiences always vary, just because there are so many variables. As far as I'm aware though, not a single person who owned a White Water and then grabbed a Cascade has seen the Cascade ever perform worse. Some see the same or a very small (~1C) improvements (typically P4 users) but do report that they can either overclock higher, or that the CPU is now more stable across a broader range of conditions when overclocked to the edge. Some see 1-2C, typically on AMD's, but even on P4's with IHS's, and the lower values tend to be with people who barely over-clock/over-volt at all, and the upper values with people who do. I've heard one person say they saw a 4C improvement on an AMD setup. I don't personally believe that such is possible under properly controlled conditions, but the person was very happy.

So what's the answer here?

If it's about that values that a test-bed spits out, one needs to be pretty sure that those values do reflect what is really going on. On P4's, one can be pretty sure that they're well off the mark.

If it's about public perception, and I won't lie much of the Cascade's "status" really is based on perception, then we go by what people report, and almost without exception it's been positive, with no one saying "I've been mislead", or "The Cascade fell well short of my expectations".

When people ask me for my take on the situation, I just want to make a block that at the end of the day I am proud to have on my system, and that I truly believe will offer the best cooling for my system. I have Intel and AMD setups here. I'm just a hobbyist who is happy to provide the same blocks that I made for myself. This is not marketing/money-making for me. If people stopped ordering blocks from me tomorrow, I'd still be happy.