Talk:Rack unit

It might be useful to get around to mentioning what it's a rack of (electronic equipment) earlier.Tom Permutt (talk) 04:09, 6 August 2021 (UTC)

Is this article really still a stub? It seems pretty well fleshed out. -dpk

"Mini-1U" - What is it?
recently ran into a product that was listed as "Mini 1U" form factor, and i was hoping to find some clarification within this article on exactly what that does, or dorsn't-much mean — Preceding unsigned comment added by 73.35.136.136 (talk) 10:40, 3 January 2019 (UTC)

Pronunciation?
Does one most commonly pronounce e.g. "4U" as "four you" or "four units"? I think this might be useful info to add. 196.215.118.141 (talk) 21:17, 15 October 2012 (UTC)

It's common to say 4U (you) also that techs have the tendency to use acronyms, it their human way of showing they have knowledge regarding that subject.

repositioning/layout fix for the picture
In both Firefox and Internet explorer with SXGA resolution, the first image goes through the horizontal rule. Just nitpicking. 75.34.28.120 06:26, 14 February 2007 (UTC)

Merging into 19-inch rack
This article is not a stand-alone article, it should really be a section in the 19-inch rack article. Any opposition? --EEPiccolo 21:27, 26 February 2007 (UTC)
 * Oppose Yes it is standalone. It is even in a different category, in case you didn't notice. `'mikka 01:01, 13 March 2007 (UTC)

I'm not sure what the wiki code is on this, but it does seem like it could easily fall into the 19inch rack article considering a Rack Unit is nothing without a rack. 69.38.135.54 13:13, 15 March 2007 (UTC)


 * salut c'est bien
 * c'est bien et toi tu vas bien ça va bien
 * c'est bien et to 176.153.143.128 (talk) 10:47, 6 May 2022 (UTC)

Oppose

This should be a stand alone article. 19" racks are not the only size. There also 23"

"OPPOSE"

I did a search using "Rack Unit" to understand the "U" terminology and got immediately to this page....which has an excellent presentation. Embedding it in a larger document would lose the information. (JP)

"OPPOSE"

This should be a standalone article and should not be merged with 19" Rack. May be we can merge other rack related article into this. (Ramki)

To mikkalai: Just because something is labeled with a different category doesn't mean it actually is a different category. It could be mis-categorized. However, I think you have a valid point, anyway. This article simply describes a unit of length. To JP: If the articles were merged, all information in this article would remain; it would just be part of a bigger article. To Ramki: If this article simply describes a unit of length, as mikkalai implies, it would be inappropriate to bring more information into this article. To anonymous: That is actually a valid point, except that this article only mentions 19" racks. I did a Google search, and indeed 23" racks exist. It would have been nice if you had edited the article to mention 23" racks, as you actually had knowledge of such things. So, in absence of any effort from you, I'll include the mention of 23" racks and remove the merge tags. To all: I don't know if you noticed, but Rack mount redirects to 19-inch rack. However, it is now revealed that there are such things as 23-inch racks! There needs to be a more general rack category that mentions both 19 and 23 inch racks. EEPiccolo 19:44, 5 April 2007 (UTC)

Porn industry?
Surely the dimensions of relay racks (an older name for 19" racks) pre-dates the use of video tape equipement in the porn industry!

VHS video tape dimension has nothing got to do with servers, so don't ruin the discussion --Ramu50 (talk) 02:41, 10 June 2008 (UTC)

Ramu just so you know there are use of racks other than in servers.--67.11.1.223 (talk) 15:59, 30 June 2008 (UTC)

Hi-Fi for example. Most studio-grade audio equiptment and some higher end scopes and other lab equiptment use 19" racks. —Preceding unsigned comment added by 81.23.50.232 (talk) 13:33, 11 December 2009 (UTC)

Anon is correct, this article focuses way too much on 'server' racks. 19" equipment (and thus racks) exist and are used in a vast number of industries, not just IT. All explicit references to 'server'/'IT'/'computing tech' should therefor be removed or edited in such a way that they do not polute this article about the rack unit. 81.83.7.207 (talk) 12:23, 22 February 2016 (UTC)

Even within IT there are more than "server" racks. The current language that universal square racks are becoming more standard is an example of this... citation still needed but it is likely true for large server 4-post racks... I mostly see square holes on new installs these days. However, it is certainly not the case for two-post racks used in networking closets. In those cases the thin metal used on square holed rails makes them too flexible to prevent the equipment from sagging, so thicker rails with tapped holes are the norm. (75.67.37.11 (talk) 14:28, 20 June 2024 (UTC))

modules and cabinet
So is the term Rack Unit and Module refer to same thing. Except RU is use for horizontally stacked server, while modules is use for vertical shelved blade servers and 24 modules is equal to 1 cabinet? I ask this, because the technician at Cray (Kraken) Supercomputer use this terminology, but i am not sure is this a common terminology. --75.154.186.99 (talk) 03:12, 18 November 2009 (UTC)


 * No, I'm not aware of the term "module" being generally associated with a specific physical form-factor. Letdorf (talk) 12:17, 18 November 2009 (UTC).

Vershok
Any significant reason why the mention that the unit is precisely equal to vershok (thus these two are just the different names for the same measurement unit) should be left out of the article? My opinion is that this equality, like an Euler's formula, brings together two distant worlds, the Ancient Russia and the modern datacenters, thus it must (not just worths to) be present in the articles. Honeyman (talk) 21:01, 22 November 2010 (UTC)


 * It could be considered somewhat trivial, but I wouldn't object to it being reinstated. Regards, Letdorf (talk) 13:14, 23 November 2010 (UTC).
 * But everything that is 1 3/4" deep, tall, or wide corresponds to a stupid vershok. Gee, do you know that 1 3/4" nails from Home Depot are exactly one vershok long? Screws too!  It's completely uninteresting that old Russians decided to give a name to 1.75 inches, a common size based on quarter-inch increments. Is this really encyclopedic info or just useless trivia?192.139.122.42 (talk) 19:52, 20 June 2011 (UTC)

History?
Does anyone have some insight to share (i.e. add to the page perhaps) about how these silly dimensions were chosen for rack units? Why is the width of a panel 19" wide, but the spacing between the screws (a much more important measure) uses some non-intuitive size invoking tiny fractions of an inch? Ironically, actual equipment deviates from the 19" panel width quite significantly anyway, and mounting holes are often oval-shaped. Furthermore, why the silly repeating pattern where groups of three holes are closer together than the gaps within each group? A design with equally-spaced holes is obviously superior, allowing for half-size increments in both size and position of equipment. Do imperial measures damage the brain so much that its users have to compound the stupidity? 192.139.122.42 (talk) 19:58, 20 June 2011 (UTC)


 * When I was young these were known as Post Office racks. I think they were used by the (British) Post office who ran the phone system in Britain. They can be seen in use on the Colossus computer at Bletchley park. The screws are space in the manner they are so units can only be placed in whole multiples of U's on a rack. I would have thought they are 19inches wide because this give "standard" 18 inches of useful space. A foot is too small and 2 feet is too large. john f 178.101.148.182 (talk) 22:05, 2 October 2012 (UTC)
 * I second this request, both here and for the "19 rack" as a whole. Those whacky dimensions look like an accidental de-facto standard, not anything designed. --Musaran (talk) 19:48, 9 February 2020 (UTC)

Unit of Measurement
Is there any reason why the measurements in the article are expressed in Imperial units and not metric units which, by the way, is the acceptable international standard and has been for decades? — Preceding unsigned comment added by 196.15.235.51 (talk) 12:03, 23 January 2013 (UTC)
 * Because these specifications originated in the USA some time ago, when Imperial units were very much the norm. SI equivalents are quoted in the article. Also, it's a lot easier to talk about "19-inch racks" than "48.26 cm racks" :-). Regards, Letdorf (talk) 23:26, 23 January 2013 (UTC).

SI units would be a lot clearer, this isn't the 1800s. Changed conversion from cm to mm in introduction. Who uses cm!? 194.150.38.93 (talk) 13:34, 28 November 2014 (UTC)

1U = 44.45 mm, not 44.50 mm
The following is copied directly from the norm IEC 60297-3-100, edition 1.0, dated 2008-11:

''5 Front panels

''5.1 Front panel dimensions

''The height increment of a front panel is 1U, equal to 44,45 mm.

Thus is would seem that the actual value of the U unit is in fact 44.45 mm, NOT 44.50 mm as stated in the article. This makes a lot of sense, since the system is obviously based on Imperial units, and 1.75 inch is in fact 44.45 mm.

I would suggest that this be corrected in the article.

Gjensen (talk) 16:43, 14 November 2018 (UTC)

template:rackunit
In conjuction with, I have developed a new template:rackunit to make it easy to give the size of an nU element in terms familiar to non-technical readers. Synax like "This is a rack-mounted server" produces "This is a  rack-mounted server". Feedback welcome. Enjoy. --John Maynard Friedman (talk) 19:55, 29 October 2021 (UTC)
 * Copied here for editor convenience. --𝕁𝕄𝔽 (talk) 16:59, 27 November 2023 (UTC)