Precision 7530 & Precision 7730 owner's thread

I performed the transplant today. New 7530 got old heat sink assembly and vice versa. I also exchanged thermal paste to Gelid GC Extreme in both laptops and left all the thermal pads as they were. I got really interesting results:

Old 7530 (with new heat sink assembly) still performs better, i.e. higher Cinebench R15 scores (but by a smaller margin) and runs quieter, while the temps are generally slightly higher compared to new 7530. On the other hand, new 7530, while maintaining slightly lower temps both in idle and under load, achieves lower Cinebench results and is louder (fans tend to spin up faster and with higher RPM). I see that under load old 7530 can maintain slightly higher clock multiplier. Another interesting observation is that the vents in old 7530 are much cooler compared to quite hot ones in new laptop.

To my knowledge, all relevant settings are identical (battery life/power slider, c-states off, Dell Power Manager set to Optimized, same BIOS version and drivers etc.).

What do you make of it? Old CPU/laptop seems to perform better, but it runs with slightly higher temperatures. Why does cooling in old laptop tend not to spin-up so fast compared to the other one, while the temps are higher? Even in idle the new one drops below 50 degrees and the fans are working, while the old remains above 50 but is completely quiet. And what do hot vents mean - is it good or is it bad? Actually, the new laptop generally feels like getting warmer under load compared to old one. Maybe there's another temperature sensor that reports higher temps in new laptop and causes the fans to run faster?

[EDIT] Under load, CPU Package seems to reach limits much faster on the new one (98 degrees, almost instantly), the old one stays lower for few seconds, although eventually reaches the limit as well. Also, CPU Package Power reaches 89.5W in the new one and only 80.5W in the old one. While the old one maintains higher clocks. How come? Maybe the difference in behaviour is connected to that... Can two exactly same CPU models differ in behaviour in such manner? If you manage to get a better one, it consumes less power for the same performance on default settings?

And another interesting observation - one of the reasons to do the heat sink assembly swap was to get rid of uneven high pitch sound in the new laptop. But it seems it hasn't changed - it's still in the new laptop, i.e. it's not caused by the fans.

 

I managed to figure out how to tame the audio latency issues on the 7530. I'm now averaging in the green in latencymon (under 1000μs) on all cores easily, and getting only one 1000-1400μs spike from acpi.sys on core 0 every 2 minutes roughly.

Here were some of the changes I made that helped me improve the latency performance:

My setup: i9-8950hk, 128GB Ram, Quadro P1000, 2x970evo 1tb + 256gb class 40 nvme. Windows
Version 10.0.17763 Build 17763

1. Enable "discrete graphics out" in bios and disable "switchable graphics." This will disable the iGPU and make everything powered through your dedicated gpu. If you have Nvidia, make sure you are using Dell's ISV certified drivers (version 419.17) from the drivers page. Also make sure you set your performance options in Nvidia Control Panel to "prefer consistent performance". This option was the only one that tamed the spikes I was getting from the nvidia kernel driver and kept it under 800μs.

2. Switch to ahci from raid if you aren't on it already, and disable intel rapid storage drivers in msconfig. For me, this made a huge difference, but its possible thats only because the 970 evos and the samsung class 40 drive (pm981) perform better latency wise with the drivers from samsung instead of the intel rapid storage drivers. It may not have an effect with different brands, but I would still try it anyway, you can switch back if it doesn't work.

3. If you haven't already, make sure you undervolt, repaste, and keep multipliers at stock so you don't get any current limit throttling (this caused acpi spikes and increasing ICCmax didn't have any effect for me.) I repasted using gelid GC extreme and undervolted in throttlestop to -.152 on the core and -.157 on the cache. I get 1345 multi, 198 single in cinebench R15 and 2800 in cinebench R20 with this current setup.

4. Make sure all usb devices have power saving turned off in device manager.

Weirdly for me, keeping c-states speedshift and speedstep all enabled gave me the best latency performance. Disabling them for me caused almost 200 more 1500μs spikes from acpi.sys per 5 minutes compared to 2-3 with it turned on. Make sure you test this yourself tho as it could vary per system.

 

So I'd been looking around at some of the lower spec 7730's, thinking I might grab one and DIY upgrade it, but then I ran across a pretty good deal on a refurb unit: 8850H, P4200, 32GB ram, 1TB NVME, 1080p, 97whr. Should be getting it next week, I'm excited to see how this thing stacks up.

 

Hi all, new here! Thanks for accepting me.

I bought a Dell 7530 and replaced the original Wi-Fi card with a Broadcom one compatible with macOS. Then I managed to destroy the MHF4 connectors on the cables :/ Now I have two choices:

1) Meticulously try to re-install brand new MHF4 connectors on the cables (they're 1.2mm thick, you can imagine how that will go).
2) Replace the entire antenna assembly (which also includes a set for the installed cellular modem).

So, has anyone had experience with either of the above? I'm weighing more towards the second solution so wondering if anyone has already done a similar job on this laptop?

Thanks in advance.

 

Replying to two messages in one...

I suppose you're hackintosh-ing? Ah, the memories of yore. I have abandoned trying to do this, because I find Linux easier to use (and forget fiddling with DSDTs and patches), and I doubt I will develop in Objective-C any more. In my previous notebook (see signature), I simply used a USB Wi-Fi adaptor, because, let's face it, Intel's Wi-Fi is best-in-class, and it was easier. Plus, I had a port to spare.

If you're still willing to keep the Broadcom adaptor, I strongly suggest you do the second: the part number is likely tagged on the antenna and cables, and all you need to do is quote that part number, and ask Dell for a new cable + antenna assembly (chances are, they will send one to you for free, since it's a very low-cost part). However, you will need to remove the screen and hence potentially change the bezels too, since they're taped to the screen, and said tape will tear when you remove the bezels.

Hmmm, interesting results. It is prudent to note that hot fins and hot air is good—it means heat is being transferred out of your CPU, into the thermal dissipation apparatus effectively. As for the new notebook, it might be a small but significant difference in background load, or even firmware revisions on the various non-BIOS chips in the motherboard. Who knows—even though the motherboards are supposed to be 100% the same, there might be differences in firmware and even the PCB traces, given different batch numbers and revisions.

 

Thanks for the quick reply!

Yeah, I'm hackintoshing. And I got the OS working without too much fiddling really so it was very easy with a vanilla install. Already upgraded twice using the normal update procedure, so I think this is a stable hack.

I do believe that they'll send me the antenna free of charge, they've already sent me a keyboard+mouse free of charge due a defective keyboard.

About the antenna's part number: since I want to continue using the laptop, I would like to know the part number even before I open the laptop. I think your suggestion is very good nonetheless and I shall send their support a request for a replacement antenna, I am guessing they know the part number anyway based on my order.

Many thanks again!

 

You can find the part number (and in fact, the entire manifest of your laptop's assembly) if you plug in your Service Tag into this website, and select 'System Configuration' --> tab 'Original configuration'. You might want to do a pattern search for 'Wi-Fi' or 'WLAN' or 'WWAN'. Dell's manifest sometimes doesn't make sense; I found mine under the display cover section. To save you the trouble, here's mine:


Methinks you want 'JY64N' or '1P2M8'.

EDIT: Looks like it's 1P2M8. From the Service Manual, it appears that the entire display cover assembly, plus the WLAN/WWAN cables come as a complete assembly, without specific part numbers for each. It also looks like you'll need to almost completely gut the laptop to replace the cables... Ouch.

Furthermore, could you do me a favour? Does your 7530 have a discrete GPU installed, from AMD or NVIDIA?

 

Hey there, and thank you so much for the complete answer!!!

My laptop has an nVidia P1000 discrete card indeed. I opted for the weakest because I don't do much 3D or rendering but need it for gaming

Looking at your laptop's manifest I see that we have the same monitor (15.6" FHD IPS, Non-touch, WLAN/WWAN Cover). I have already contacted Dell asking how much such cover would cost. If it costs a lot then I may eventually buy a damn magnifier and a cable stripper and do the installation of MHF4 myself. How hard can it be when I see the parts magnified 50 times?

Answer: hard! Video for a Mac fix, mute the horrible music:



Thanks again!

 

@NikoAyc,

Thanks for the reply. I was actually looking for someone who didn't have a graphics card in their system, because I am currently investigating battery power draw in these notebooks... Anyway, all the best in replacing your cables. If you're not using the cellular antenna, you might consider repurposing it and the cables for Wi-Fi, too—I think the connectors are the same.

 

Yeah, they're the same. I may do that actually but for now I just bought a USB Wi-Fi card that works fine. But still, I'd like to get this laptop to its top condition... I think I'll just rewire the cables myself or through a 3rd party lab.

Sorry I couldn't be of much assistance there... For the record, my laptop doesn't drain that much battery power but that may be because I mainly write code on it.

All the best!