We only know the option to look at the device id in Windows, but for that you have to start the system up and finish the Windows installation - both not that easy for sellers.
Dell may be able to tell you but thats something I cant tell you if they can or will.

I read somewhere that not all 5550's have the Samsung ISP display (as tested in notebookcheck.com reviews). Is there a non-invasive way a seller can verify if the laptop being offered has the Samsung display? In case the seller doesn't know, I'd like to instruct them on how to check.

OR, if I can get the service tag #, would Dell be able to tell me which display it has, at least had when it was new?

I don't thing the GPU influences the display much (well there are color settings done there too, but thats then again back to configuring the device).

Thanks, Klaus. I originally was looking for a Broadwell 5550 but the display metrics in the review gave me pause. One thing I noticed is that the graphics adapters are different (HD 5500 for the Broadwell model vs. HD 4400 for the Haswell). OTOH, I wouldn't think the graphics adapter would affect most of the display metrics, such as contrast, cited in the review.

Since Broadwell CPU performance is only marginally better if at all, I think I'll go with the Haswell 5550.

Thats something we see sometimes and cant really explain. There is a lot of tuning that can be done using PWM, backlight and other settings that a manufacturer can do and also different model years may produce a different panel quality.

I'm in the market for an E5550. This model was significantly improved from its predecessor E5540, which may explain why Dell chose to initially ship with a Haswell CPU ahead of Broadwell's release.

I just read the two excellent reviews posted here on Haswell (i5-4310U) and Broadwell (i5-5300U) versions. These reviews were extremely helpful. (Sorry, as a new member, I can't post links to the reviews.)

But one thing stood out in the performance tables that wasn't addressed in the review commentary... Why is Haswell 5550's display performance so much better than Broadwell given that both review laptops apparently had the same Samsung ISP display? Can anyone shed any light on this?

Since the Broadwell 5550 review was largely a comparison with the Haswell 5550, I was surprised Sasha didn't comment on the large differences in contrast as well as virtually every other display metric.