OK, I’ll take a little break from testing and share some of my thoughts…
Fact: Thermal die simulators are just that – simulators. They can provide useful data (especially for waterblock designers) but rarely give a true representation of how a waterblock will perform on a particular CPU under specific conditions. Intel has the resources to build a better CPU simulator (the TTV), which should more accurately reproduce some of the dynamics of a real processor - but its still just a simulator. I agree with what others have said: what we really need is much better correlation between the simulators and real CPU’s. IMHO simulators will continue to be useful and different simulators will produce different data.
I have been wrestling with many of the issues being discussed in this thread for some time. I know my current 14mm naked copper heat die is becoming outdated and have given a lot of thought to its replacement. Here is what I have come up with so far (see attached sketches).
New Features:
+ Incorporates a removable copper heat spreader
+ Extended die height so extra sensors can be added to calculate heat flux
+ Thermocouple (or RTD) is mounted into the heat spreader (this eliminates variability’s in the heat die to heat spreader joint)
+ Heat die is spring-loaded to insure good contact pressure at all times
+Integrated 0.01 ohm, 50W shunt resistor for more accurate Amp measurement
Standard Features:
+ Two cartridge heaters (0~300 watts)
+ Copper die
+ Phenolic deck (very rigid, easy to machine, OK insulator
+ 6-32 threaded inserts (mounting patterns for popular AMD and Intel CPU’s)
+ Ceramic felt insulation (Cotronics)
To Be Determined:
· Heat spreader surface area (32mm sq?)
· Heat die surface area (14mm sq?)
· Spring load force (~20 lbs ?)
· Spacing and location of optional temp sensors (to measure heat flux)
This 4th generation thermal die is intended to better simulate current processors that use an IHS and have larger die areas. It also provides a much more robust test surface that should hold up longer before neading to be re-lapped or replaced. The temperature probe is mounted into a tiny hole drilled into the bottom of the copper heat spreader and is potted with thermal epoxy. The temp probe lead wires exit thru a hole drilled up thru the center of the heat die. This places the temp probe ~0.5mm from the top surface and eliminates the variability’s caused by the TIM joint.
I envision making/using a separate tool to hold the copper IHS during machine lapping.
To address the problem of consistently seating the waterblock being tested onto the thermal die simulator without adversely distorting the IHS, I included a spring under the heat die, which pushes up (exact force TBD) insuring the heat die is making good contact with the bottom of the IHS (and waterblock base) at all times. When the waterblock is first mounted it will engage the top surface of the IHS and push the whole assembly down (~1/8”?) until the outer rim of the IHS firmly seats against the insulated Phenolic deck. The spring pre-load force pushing the heat die up is adjusted by: (1) spring selection and (2) length of standoffs used to mount lower spring platform.
The top Phenolic deck plate uses threaded inserts located at the common CPU mounting hole locations (just like my current design). Alternately, a universal mounting frame could be attached to the deck to allow clip-style mounts to be tested (I don’t plan to go this route).
The lower heat die and upper Phenolic deck are covered with ceramic felt insulation (1/8” thick), which allows the heat die to slide up and down thru the square opening in the deck. The entire assembly is then surrounded with ceramic fiber insulation and housed in a small enclosure.
Side note: Today is Thanksgiving Holiday in the USA…
HAPPY THANKSGIVING!
Thanksgiving is an attitude… I am very thankful this day for the MANY blessings God has granted me (family, friends, a job, freedom, good health… and access to a global community of PC enthusiasts like you!)