Talk:ILLIAC IV/GA1

GA Review

Article (edit | visual edit | history) · Article talk (edit | history) · Watch

Reviewer: David Eppstein (talk · contribs) 23:18, 27 January 2018 (UTC)[reply]

On the whole the prose is of good quality (criterion 1a), but it relies heavily on acronyms some of which are defined well after they are used (IAS, ILLIAC, ARPA) or are never defined (PC board). I think it would be better to avoid this style and spell out technical terms like "control unit" wherever they appear.

The lead section should consist of a summary of the material from other sections, and when doing so it does not need citations (MOS:LEAD, criterion 1b). But instead the claims in the first paragraph (that it was one of the earliest massively parallel computers, that the original design had 256 FPUs and a single CPU, that it could process large array data, and that its instruction set made it SIMD) are unsourced, do not appear to be summaries of anything later in the article, and in some cases contradict the article (which says that there were 256 units that could be partitioned into multiple FPUs each, and that theere were four control units). Similarly, the claim in the second paragraph that Slotnick's original idea for this specific machine was in 1952 is not a summary and is unsourced. And the end of the second paragraph ("instead of 1024") contradicts the claim in the first paragraph that the original plan was for 256 processors. The claim in the third paragraph about a new facility is sourced, but not a summary. And again, many claims in the fourth paragraph are neither sourced nor summaries.

The references are consistently formatted (criterion 2a) and appear reliable (criterion 2b).

It would have been helpful to have a link for the Falk reference (the actual title appears to be "What went wrong V: Reaching for a gigaflop: The fate of the famed Illiac IV was shaped by both research brilliance and real-world disasters" and it can be found at https://doi.org/10.1109/MSPEC.1976.6367550). The Slotnick's link is ok, but https://doi.org/10.1109/MAHC.1982.10003 is I think more permanent. And similarly the Barnes link is ok (and has the advantage of not needing subscription access) but the official link would be https://doi.org/10.1109/TC.1968.229158

Detailed checking found the following additional issues with sourcing (criteria 2c and 2d) beyond the unsourced claims in the intro:

"It is also credited with being the first supercomputer to use solid-state memory", "Generally considered a failure": not found in Falk p.65 (footnote 1). The closest I can find to the "failure" claim is on p.68, and credited to "one of the men" on the project rather than as a general opinion.
"The IAS machine was...": the MacKenzie source is good for the claims that it read words one at a time and operated on them in bit-parallel fashion, but not for "fairly conventional" (MacKenzie suggests instead that it was a trend-setter rather than a follower), nor the 40-bit word size, nor the comparison with present-day architectures, nor the 80-track drum size, nor the 1024-word main memory, nor the comparison of scaling behavior between word-serial bit-parallel and word-parallel bit-serial. In conclusion, much of the "Origins" section is falsely sourced, with footnotes that have nothing to do with the claims they appear to source.
"left the IAS in February 1954 to return to school for his PhD" is I think too closely paraphrased from the source "left Princeton in February 1954 to return to school for a Ph.D."
"a college, John Cocke": he's an institution of higher learning? (The correct word would have been "colleague".)
"ended up at IBM in 1958": the source says that this is when Slotnick started thinking about parallel computers again, not when he joined IBM.
"After a short time at IBM and then another at Aeronca Aircraft, Slotnick ended up at Westinghouse's Air Arm division, which worked on radar and similar systems. Under a contract from the US Air Force's RADC, Slotnik was able to build a team": none of these things are in the only source for the paragraph, MacKenzie.
"SOLOMON's CU would read instructions from memory, decode them, and then hand them off to the PE's for processing.": not in the source, and potentially misleading. I am not convinced from what I see at the source that the program store for SOLOMON was the same thing as the memory it used for its data, as it would be in a modern computer.
"the PE Memory module, or PEM": these names are not in the source.
"The CU could access the entire memory via a dedicated memory bus": not in the source, and very confusing. What is the CU supposed to do with data values stored in the memory? Its function is to control the other units, not to make calculations.
"Although there are problems, known as embarrassingly parallel, that can be handled by entirely independent units, these problems are generally rare.": off-topic for a discussion of the detailed hardware design of an ILIAC predecessor, and entirely unsourced.
"A single PE using this design was built in 1963.": the source says "We built experimental PEs" (plural) and gives the broader date range 1962–1963.
"This evolution toward a smaller number of more complex PEs would continue under ILLIAC IV.": not in the source.
"no further funding was forthcoming": the source talks about "the shutoff of most of our DOD funds", not quite the same thing.
"who at that time had been at the forefront of supercomputer purchases": contradicted by the source, which instead says "only slowly became important customers".
"Westinghouse management considered it too risky...take on the development costs.": the footnote says p.118 of MacKenzie but this material is on p.119.

At this point I got tired of finding problem after problem and stopped looking for more. Almost every single footnote and almost every single footnoted claim up to this point has something wrong with it. The article needs a thorough sentence-by-sentence check of whether what it says can be justified by what's in the sources. Only then will it be ready for GAN.

The article is on a specific topic so criterion 3a isn't really an issue, but there is a lot of component-by-component detail of machines that are not ILIAC IV; is this really necessary (criterion 3b)?

There are no issues with neutrality (criterion 4) or stability (criterion 5).

However, I think File:SISD, MIMD and SIMD computer processor designs.svg may be somewhat problematic (criterion 6). Essentially, it looks like a stealth way of introducing editorializations about the relative merits of different processing architectures into the article, without properly sourcing them. And at the size used for the article, it is completely illegible.

Conclusion: This is a long way from meeting criterion 2 (proper sourcing), and as such does not pass GA. Additionally I have significant concerns about criteria 1b (lead does not summarize article) and 3b (overly detailed about tangential topics). But in other respects the article looks pretty good, so once these issues are handled the article may be ready for another attempt at GA. —David Eppstein (talk) 01:13, 28 January 2018 (UTC)[reply]

Hi David, thanks for the notes.

"The lead section should" - many edits here to clarify. Last para will have to wait until tomorrow.
"The IAS machine was..." - wrong page number, was really 295. Changed to use Slotnick.
"It is also credited with being the first supercomputer to use solid-state memory" - this is stated pretty directly in Falk, who states that such systems had been used only experimentally up to that point and no one had used it for the basis of a machine.
"Generally considered a failure" - I believe this is accurate. Googling "illiac iv failure" turns up any number of useful direct hits in Books. Select any one you like and I'll use it instead.
"I think too closely paraphrased" - I'm going to leave that.
"a college, John Cocke" - fixed.
"ended up at IBM in 1958" - fixed.
"After a short time at IBM" - fixed.
"I am not convinced ... program store for SOLOMON was the same thing as the memory it used for its data." - it wasn't and it doesn't say that. It very clearly states that program instructions were in one store and that "Each PE had its own memory for holding operands and results". This is mentioned in pretty much every ref.
"the PE Memory module" - fixed
"What is the CU supposed to do with data values" - ...reading and writing them, among other things; the CU was scheduling I/O, running some processing, and many other tasks. This is definitely mentioned in the source, and the new one I added. The new one has a diagram on 376 that shows how all o this worked.
"Although there are problems" - removed.
"This evolution toward a smaller" - removed
"who at that time had" - MacKenzie describes the lab's involvement in computing as "epoch making" and has published a number of other papers widely making this statement.
"the shutoff of most of our DOD funds" - I'm happy with the wording as it is, Westinghouse ended the project at that point and I don't think the wording is misleading. If the reader wants to know the complete details, they can read the (easily readable) reference.
"only slowly became important customers" - "for massively parallel architectures". The statement in the article is talking about general computer purchases, not parallel machines specifically.
"Westinghouse management considered" - fixed.

More, more! Maury Markowitz (talk) 14:47, 28 January 2018 (UTC)[reply]

Let me clarify, since this doesn't seem to be reflected in your response. I don't just want you to fix the specific problems I identified. What I want is for you (or anyone else tempted to re-nominate this for GA) to do the same line-by-line checking of claims in the article against claims in the source that would be expected of a GA. You should find most of these problems yourself, rather than hoping that a reviewer would find them for you. The GA review process is supposed to be about recognizing articles that are already high-quality, not about how to revise your article so that it becomes high-quality. —David Eppstein (talk) 00:14, 31 January 2018 (UTC)[reply]

I understand, but as that task will take a while, I'm interested in more comments on the prose and organization. The talk page of the article says that the GA is closed, but looking on this page I do not seem to see that indication. In any event, I would like to leave this open to gather additional comments from other reviewers. Maury Markowitz (talk) 22:04, 3 February 2018 (UTC)[reply]