If we compare the 8 GB and 16 GB modules, they are identical at first glance. Only at second glance do differences in the layout of the PCB and the positioning of the memory chips become apparent. While the 8 GB modules use the A2 PCB layout, where the memory chips sit a little further out, the 16 GB modules use the B1 PCB layout. Together with the identical heatspreader, this results in a memory chip not being covered at all by the heat sink plate and its thermal pad in the case of the single-sided 8 GB modules. Especially with the relatively heat-sensitive Samsung 8 Gbit B-Die IC, I see potential stability problems here at high overclocks due to the exposed chip.
Speaking of heat, the modules unfortunately do not have a temperature sensor. So the SPD package with the engraving “44 5M E68” is really just an eprom. Also, at second glance, it is noticeable that there are slight variances in the mounting of the heatspreader between the modules, see chrome elements on the acrylic or silver anodized bezel. But for these small irregularities we want to turn a blind eye, besides they should probably not fall into the same for most users anyway.
By the way, disassembling the heatspreader is only recommended if you don’t want to reuse it, because the partly very filigree elements are all glued together and it would be difficult to restore the original condition. Since these modules must be returned to the manufacturer after the test, I have accordingly decided to do without a teardown.
Of course, we can still examine the performance of the heatsink. For this we use as usual a type-K temperature sensor in the middle of the outer DIMM between heatspreader and PCB for the module temperature and a second temperature sensor for the ambient temperature. The stress test used is Testmem5 v0.12 with the profile Extreme1@Anta777. The sensors are polled 10 times per second over 45 minutes, the values are logged and then the delta of the two is plotted. For both kits a layout is tested on a 2 DIMM mainboard without space between the modules and on a 4 DIMM mainboard with one slot space between the modules. All configurations use the XMP profile with 1.45 V RAM voltage.
Even after more than 30 minutes in TM5 and in the most thermally unfavorable scenario with two double-sided modules directly next to each other (DR, 0 DIMM spacing), the warmer module reaches a maximum of 21 °C above room temperature. Considering that the maximum operating temperature for DDR4 is specified at 85 °C according to JEDEC, this result is very good and reveals a lot of thermal potential for overclocking with higher voltages.
Especially at voltages above 1.5 V, Samsung 8Gbit B-Die is known to have a tendency to become unstable and wants to be kept below 50 °C. In this respect the test results for the heatsink performance look promising, although of course an average temperature in the middle of the board is of course not meaningful for the condition of individual memory chips, of which – as seen earlier – not all are covered by the heatsink in the single-sided modules.
42 Antworten
Kommentar
Lade neue Kommentare
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Urgestein
Alle Kommentare lesen unter igor´sLAB Community →