Among the most obvious benefits of harnessing the power of water-cooling is the ability to daisy-chain multiple devices for the CPU, Graphics, Chipset, and even memory.
Up until now, the most common way to do this has been to connect the waterblocks in series. In this type of configuration however, the pressure drop generated by each one of the devices cumulates, which substantially reduces the overall flow rate in the loop; and as the flow rate diminishes, so does the thermal performance of the system. Many extreme users have been resorting to adding a second pump to their system to mitigate this effect.
Up until now, the most common way to do this has been to connect the waterblocks in series. In this type of configuration however, the pressure drop generated by each one of the devices cumulates, which substantially reduces the overall flow rate in the loop; and as the flow rate diminishes, so does the thermal performance of the system. Many extreme users have been resorting to adding a second pump to their system to mitigate this effect.
There is another strategy to connect multiple water blocks: the parallel configuration. It is very advantageous because in this type of setup, whentwo devices are parallelized, the flow is divided in half, but the pressure drop is divided by a factor of four, thus alleviating the need for a second pump. However, it necessitates splitting the main line using Y connectors, and it is seldom used because connectivity is awkward and cumbersome.
Enter the Multi-port Apogee HD waterblock, and MCR DriveRev3 Radiators. Withtwo additional outlet ports for the Apogee HD andtwo additional inlet ports for the MCR DriveRev3 radiator, it is now possible to conveniently setup a high flow multi-block loop without using splitters. We will show below that while it always remains preferable to keep the CPU waterblock in series with the main line whenever possible, all other electronic devices in the loop are perfect candidates for parallelization. The resulting configuration is a mixed serial + parallel setup, i.e. the best of both worlds!
The following flow-chart compares two extreme setups (CPU + triple SLI + chipset + memory) serving to illustrate the increased flow performance that can be obtained from using a mixed serial + parallel configuration:
As mentioned earlier however,the consequence of parallelizing cooling devices is that the flow rate inside of said devices is also divided,thereforeslower. So we now need to introduce another concept to further qualify the rationale behind parallelization: the heat flux generated by the different electronic devices, i.e. the rate of heat energy that they transfer through a given surface.
CPUs
Modern CPUs generate a lot of heat (up to and sometimes higher than 200 W), which is transferred through a very small die surface (the die is the actual silicon, and it is usually protected by a metallic plate called a heat spreader or IHS). Among other things, what it means in practical terms is that higher flow rates will have relatively more impact onthe CPU operating temperature than on any other devices. For this reason, and in most configurations, the Apogee HD CPU waterblock will preferably always be connected in series with the main line, so it can benefit from the highest possible flow rate.
ALL other devices except radiators
GPUs, whether they have an IHS or not, also generate a lot of heat (sometimes even more than CPUs). However the physical size of the dies is substantially larger than that of any desktop CPUs. The resulting lower heat flux makes GPUs much less sensitive to flow rate. In fact, when both are liquid cooled, we can readily observe that the GPU operating temperatureis always much lower than that of the CPU. For this reason, it is 1/ always preferable to parallelize multiple graphics cards with each-other, and 2/ when one or more GPU blocks are used in conjunction with one or more other devices like chipset and/or memory, it is always beneficial to parallelize the GPU(s) with said devices using the Apogee HD multi-port option.
Chipsets, Memory, Hard Drives and pretty much everything else one would want to liquid cool in a PC can also be placed in the same use-category as GPUs, either because they have a low or moderate heat flux, or because the total amount of heat emitted by the devices can be handled withoutsophisticated cooling techniques. What it boils down to, is that they are even less flow-sensitive, and we submit that parallelization of these blocks should in fact become a standard.
Radiators
The higher the flow rate inside of a radiator, the quicker it will dissipate heat. For this reason, radiators will always remain on the primary line, just like the CPU block, in order to benefit from the highest possible flow rate.
In conclusion, we can see that the multi-port Apogee HD when coupled with the MCR DriveRev3 radiators makes a compelling case for optimizing complex loops: it maximizes the flow rate where it matters most (on the CPU, and radiator) while offering a splitter-free parallelization of up to three other components (GPUs, chipset, etc.).
Alternate configuration:
The Apogee HD allows an alternate configuration: by using the main outlet as an entry port instead of the inlet, you can then parallelize the CPU with up to two more components: a second CPU, a GPU, a Chipset, etc. While it remains true as explained earlier that CPUs benefit from higher flow rate than other components, the few degrees in performance gains might not be consequential to some users. In these situations then, using the alternate configuration could for example be beneficial as follows:
When cooling two CPUs, it might be desirable to parallelize them in order to maintain the exact same temperature for each CPU.
For one of the quickest upgrades ever: one could get started with a CPU-only loop, and use the alternate configuration initially. Then when installing additional water-blocks (graphics for example), all would be needed is to drain the liquid out, replace the plug(s) by fitting(s), and connect the tubes to the new device(s). There is no need to remove the Apogee HD, no need to remove and recut tubes to length: the existing loop doesnt need to be modified.
Tab 2
Pressure Drop Specification: The apogee HD has approximately 30% less pressure drop than the Apogee XT Rev2, as shown in this graph:
Comparative Temperature Data:
The followinggraphs reports the data collected from testing performed with actual retail processors under 100% load using CPU Burn. Published results are the best of a minimum of 5 mounts. These results are indicative of our test bench settings and of the tested processors only. Results may vary from one processor to another. Competitive data is provided hereafter for comparative purposes, and is only representative of the specific waterblock samples tested here. Two samples of the same competitive blocks were used for validation purposes.
Note: "Temperature Delta" meansthe difference between the average CPU core temperatureand theaverage air temperature. This reporting method reflects the true efficiency of the cooling systembecause it eliminates ambient air temperature variations in the data being compared. Users are cautioned that the above data is provided for reference only, and isnot directly comparablewith CPU temperature values collected a) from an enclosed chassis and b) without deducting ambient air data.
Test Setup Configuration:
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Open bench MCR 320 Drive Rev3 with (3) Gentle Typhoon Fans running @ 1850 rpm
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MCP35X pump running @ 4500 rpm
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Air temperature as reported by (3) individual thermal probes located at each fan inlet, with air temperature values collected at one second intervals and mathematically averaged over the duration of the test.