Comparative Ellipsis in Benchmark Comparisons

"The new indexing algorithm runs faster than the old one" correctly uses comparative ellipsis: the repeated verb "runs" and even the repeated noun "algorithm" (replaced by "one") are omitted after "than", since restating them would be redundant. Option A repeats the full clause "the old indexing algorithm runs" unnecessarily, which is grammatical but verbose and not the ellipsis pattern being tested. Option C adds an extra, ungrammatical object "it" after "runs". Option D creates a confused, ungrammatical mix of auxiliary inversion and a repeated verb.

"The read replica handles as much traffic as the primary does" correctly uses ellipsis with the auxiliary "does" standing in for the repeated verb phrase "handles traffic", the standard way to avoid redundancy in "as...as" comparisons. Option A spells out the full repeated clause, which is grammatical but not the concise ellipsis pattern intended here. Option C incorrectly uses "is" instead of "does" to stand for the action verb "handles". Option D inverts the subject and auxiliary ("does the primary"), which is not standard word order for this kind of comparative ellipsis.

"Run A used 2GB of memory, Run B 2.5GB, and Run C 3GB" correctly uses gapping, a form of ellipsis common in parallel benchmark reporting, where the repeated verb "used" is omitted entirely from the second and third clauses since it is recoverable from context. Option A spells out "used" in every clause, which is correct English but not the ellipsis pattern being tested. Option C incorrectly leaves "used" dangling with stray commas, producing broken parallelism. Option D incorrectly uses "did" as a substitute verb, which is not the standard gapping pattern (gapping omits the verb rather than replacing it with "do").

"Response times were higher than expected" correctly uses the common ellipsis pattern "than expected", omitting the full clause "than they were expected to be", which is standard, idiomatic phrasing in performance reports. Option B unnecessarily restates "it was expected", which is also redundant and slightly awkward given "response times" is plural, not "it". Option C is a wordy, ungrammatical restatement. Option D scrambles the word order into an ungrammatical sequence.

"Configuration B had lower latency than Configuration A" correctly uses ellipsis, omitting the repeated verb phrase "had latency" after "than", leaving just the compared subject, the concise and standard way to phrase this comparison. Option A spells out the redundant repetition "had latency" again. Option C incorrectly repeats the comparative adjective "lower" as well, which would illogically claim Configuration A also had unusually low latency relative to itself. Option D incorrectly inverts subject and verb ("had Configuration A"), which is not standard word order for this ellipsis pattern.