Dell Precision M3800 Owner's Review

Thank you for the great review (and helpful answers). I think your review is convincing many to buy XPS15/M3800.

I wouldn't add another 10 Watts, as it seems unlikely to see both 750 and Iris Pro drawing power at the same time. Anyway, my understanding is that MBP draws power from battery when its AC adapter cannot feed enough power by itself (they had been doing this ever since they made it impossible to remove battery from MBP). Obviously, it won't work for long, but it works for short time, guess -- and most use cases won't see max power draw for sustained amount of time. Being Apple, having smaller AC adapter probably is more important for them.

 

Ah, so even if Iris isn't used, it would still have a max TDP of 47W for the 4960HQ? That's not looking good.

Although, many guys on the Mac forums mention that >85W draw gets offloaded to the battery. One guy mentioned about 5% drain per hour while playing BF3.

 

That is about right, since the MacBook Pro turned Quad Core, the battery drains under heavy usage. On my cMBP I can get the battery to drain with just max CPU load and max brightness, not even touching the dGPU. I would say for heavy work like 90%+ utilization on both CPU and GPU the battery will drain in about 18 hours. While that may not be a problem for most this is a huge problem for people with heavy workloads that require extended time to run. Also, think about what happens in a few years when the battery health is near gone. You will run at normal performance for maybe a few hours before getting locked into the lowest clock speed for both CPU and GPU.

They really need probably a 120W power adapter. Even then the system still may not charge under load.

 

Most games don't fully load the CPU and GPU at the same time. Crysis 3 does. Flight sims and MMOs probably will. Under most situations, users probably won't notice an issue with the 85 watt adapter. Dell Precision machines always have power supplies and cooling to run at full speed without throttling under all situations.

Most of what I don't like about the M3800 is based on my personal preferences. I try to leave as much of that out as I can since it won't matter to other people. I wish it had a mechanical wireless switch, but other people will like the machine as uncluttered as possible.

I saw that the XPS 15 has a dual core option with no graphics card. That would be a deal-breaker for me. The cpu maxxing out with the dual core ULT i7-4600U is one of reasons I am not interested in the new HP ZBook 14. I would not buy an M3800 with a dual core processor or without the K1100M.

I also saw that the XPS 15 has 15.6" 1080p touch panel with 72% color gamut and another non touch panel with only a 60% gamut and lower contrast/brightness. The 1080p touch panel actually has the same specs as the QHD+ screen. Hopefully the 72% screen will be the base model option available on the M3800. It would make me happy to see the Precision line go 72% or higher across all systems and all configs.

Scaling works well with Windows 8.1. My guess is that it will keep getting better as more software updates come out.

 

I've been playing with scaling on Windows 8.1. For the most part it works great. Some apps don't support it properly which generally means that elements just look blurry when scaled up. (Same thing happens on OS X with old apps.) Some apps have minor issues here and there (see Bokeh's notes about the menus in some Adobe apps). There are a few apps are flat-out broken. For example, trying to play a video with VLC, it seems to not be able to figure out where the frame is and I can only see a top-left portion of the video. Anyway, hopefully more and more apps will add proper support now that high-DPI displays are making a serious appearance.

For desktop apps, you can choose the scaling ratio as a percentage so you can pick the one that is right for you. For example, with the 3200x1800 screen, setting the scaling ratio to 200% would give you an effective 1600x900 working space with everything pixel-doubled in size. You could set the ratio to 150% and get something like a 2133x1200 working space with everything 50% larger. There are some default choices for the scaling percentage, but you can pick any value that you like.

You can set a different scaling ratio for each display. However, Windows renders the app as it would appear on your primary display and just scales the image up or down from there if it is actually being shown on a secondary display. So, for best results you should have the same scaling ratio for each display; failing that, your highest-DPI display should be set as the primary.

"Modern" / "metro" apps seem to be handled differently with even a separate control panel setting for scaling. The choices are "default" and "larger," which appears to pixel-double everything.

 

Wait, are you saying the m3800 doesn't down throttle at all? Also, do you know if it has just one heatpipe like the Macbook Pro?

I think I also recall you saying that the CPU is running at turbo the entire time. Why would they do this instead of letting it adapt to user needs and save a lot of battery life?

 

Yes and no...
The Crystalwell 128 MB on package die operates independently of Iris Pro as a L4 cache and uses between 0.5W at idle to 4.5W at full bandwidth.
The CPU core is also the full 8 MB L3 cache with 2 MB used for L4 cache tagging so only 6 MB is actually available for the L3 cache.
Depending on workload the PCU has to account for that ~5 watts of the eDRAM + 2 MB L3 cache

The 4702s also have a cTDP up mode of 45W @ 2.9 GHz for all 4 cores.
It will be interesting if Dell ever allows this to be activated.

 

Yes, it has one large continuous heatpipe that runs between the two fans. See the pic on the first page.

When plugged in and running Prime95 and MSI Kombustor at the same time, the CPU and GPU do not throttle. In fact, the CPU stays in turbo mode the whole time even when it and the GPU are both fully loaded.

When there is a light load or the system is at idle, the CPU slows down to not waste power. Sorry for the confusion on that one.

They do allow it, but only for about a minute. Clocks then fall to between 2.6 and 2.7 for as long as a full CPU load is present.

 

I'm becoming more and more impressed with the m3800 and will probably go for it (especially if Dell has some sort of discounts like Apple does for education).

There's a similar thread on the MacRumors forums about the XPS 15 vs MBP and one of the guys (clear Apple fanboy from how hash his post is) suggests that build quality is not on par.

He suggests that it's not unibody and that the carbon fibre is just for show kind of like an added on sticker. I'm guessing most of what he says is inaccurate but I'd like your take on it.

""It's NOT machined Aluminum, it's stamped Aluminum with some machining, which is nowhere near the same quality. The build quality is incredibly terrible on the XPS 15 in comparison. Apple makes their machines out of solid blocks of aluminum that have laser cut sections. There is no comparison between these two construction techniques. This is the highest quality and strongest manufacturing process available. Dell uses a cheap imitation of this process, that is 4-5 times weaker structurally. The carbon fiber is also a mass produced flat sheet that costs cents, with no custom forming whatsoever. It's just bought in massive sheets for a few dollars and then cut to size. It's insultingly cheap and also incredibly tacky and literally screwed onto the top cover, it would look better without it.

I've had computers made with the machined aluminum like Dell use. Being dropped from a few feet the entire cased cracked. Dropping my macbook in the exact same situation from the same desk just resulted in a small dent. Cheap manufacturers use cheap brittle aluminum that cracks with the smallest amount of force. It's really misleading because it's not the durable material you think you're getting. Dell and HP use the same aluminum alloy that hotwheels uses for their toys, which is 6061, and it's not made from solid blocks but sintered, which means it's made from a powder that is melted together and full of structural weaknesses inside every inch. This is around 4-5 times weaker than the 2024-T3 alloy which comes from a solid block.

Sintered 6061 is held together a lot like a sugar cookie and it's very brittle in the same way. It has a tensile strength of around 40 MPa if they use a high quality process. 2024 has a tensile strength of 220 MPa.""

 

No sources noted there. He can be a Mac fan, but to say that the XPS15/M3800 has horrible build quality when they have never seen or held one is stupid. My wife would say he is talking about boobs when his only experience with them was in a Playboy magazine. Will get the specs on the Aluminum and post them, but the aluminum on the M3800 is machined and very strong. I have a small dent in it from a very hard hit. Certainly not sugar cookie brittle. The carbon fiber bottom in not a sticker, it is a heat shielding strong material. They make motorcycle muffler shields out of carbon fiber to protect against burns. The carbon fiber also has a ton of custom forming and curves to it. The macrumors fanboy has no idea of what they are talking about.

So. lets actually back up those statements....


Custom forming on the carbon fiber bottom.


More custom forming and bulking up on weak spots up front.


The damage from a very hard hit to the machine on a metal bar. It was slammed when a kid on a bike ran into me. I was sure the machine was broken.

Also, note the machine marks on the aluminum trim.