Checked 30 September 2026. Based on the official 2027 syllabus PDF (IIT Madras) and the GATE 2027 brochure revised 27 September 2026. The comparison is our reading of the two official texts; the organiser has not published an itemised change list.
GATE 2027 is organised by IIT Madras, and its notice of 20 July 2026 announced that the syllabi of the papers had been revised. It did not say what changed. For Computer Science and Information Technology, we compared the official 2027 syllabus PDF with the official 2026 one (IIT Guwahati), word by word.
The result: seven of the ten sections are word for word the same. Three were rewritten: Digital Logic, Computer Organization and Architecture, and Computer Networks, which lost more than any other. Separately, CS candidates can now pair their paper with Mechanical Engineering (ME) or the new Robotics and Automation (RA) paper. The comparison below is our interpretation of the two official texts, and we quote both so you can judge it yourself.
Our comparison of the official 2026 and 2027 syllabus PDFs and the two brochures.
Where other pages get this wrong
"Socket API" is not a new topic, and disk questions have not been declared removed.
Commonly published instead: Change lists that call socket programming newly added to GATE CS networks, or say disk scheduling has been dropped.
The 2026 syllabus already listed "sockets" under the transport layer; 2027 says "socket API". And while "secondary storage" is no longer named in Computer Organization, the Operating System section still lists file systems and I/O scheduling. The safe reading is that disk questions are no longer named in COA, not that they are gone.
Compare any section
GATE CS syllabus: 2026 vs 2027, section by section
Choose a section to see the official 2026 wording, the official 2027 wording, and our reading of what changed.
Wording is copied from the two official syllabus PDFs. The "what changed" line is our interpretation; the organiser's notice of 20 July 2026 says only that syllabi were revised and does not itemise the changes.
The same comparison as a table:
| Section | GATE 2026 wording | GATE 2027 wording | What changed (our reading) |
|---|---|---|---|
| Section 1: Engineering Mathematics | Discrete Mathematics, Linear Algebra, Calculus, Probability and Statistics (same wording in both years). | Identical. | Unchanged. |
| Section 2: Digital Logic | Boolean algebra. Combinational and sequential circuits. Minimization. Number representations and computer arithmetic (fixed and floating point). | Boolean algebra and minimization – algebraic technique, Karnaugh map, tabular method. Design of combinational and sequential circuits. Number representation and arithmetic (fixed and floating point). | Rewritten. The minimisation methods are now named: algebraic technique, Karnaugh map and the tabular method. "Combinational and sequential circuits" becomes "Design of combinational and sequential circuits". "Computer arithmetic" becomes "arithmetic". |
| Section 3: Computer Organization and Architecture | Machine instructions and addressing modes. ALU, data-path and control unit. Instruction pipelining, pipeline hazards. Memory hierarchy: cache, main memory and secondary storage; I/O interface (interrupt and DMA mode). | Instruction set and addressing modes. Design of arithmetic and logic unit (ALU). Design of control unit – hardwired and microprogrammed. Memory interfacing and hierarchy: performance, cache memory mapping. I/O interface (interrupt and DMA). Instruction pipelining, pipeline hazards. | Rewritten. Newly named: design of the ALU, hardwired and microprogrammed control, memory interfacing, memory performance and cache memory mapping. No longer named: data-path, main memory and secondary storage. "Machine instructions" becomes "Instruction set". |
| Sections 4 to 9: Programming and Data Structures, Algorithms, Theory of Computation, Compiler Design, Operating System, Databases | As printed in the 2026 PDF. | Same words as 2026. | Unchanged in all six sections. |
| Section 10: Computer Networks | Concept of layering: OSI and TCP/IP Protocol Stacks; Basics of packet, circuit and virtual circuit-switching; Data link layer: framing, error detection, Medium Access Control, Ethernet bridging; Routing protocols: shortest path, flooding, distance vector and link state routing; Fragmentation and IP addressing, IPv4, CIDR notation, Basics of IP support protocols (ARP, DHCP, ICMP), Network Address Translation (NAT); Transport layer: flow control and congestion control, UDP, TCP, sockets; Application layer protocols: DNS, SMTP, HTTP, FTP, Email. | Principles of Layering; Basics of switching (circuit, packet and virtual circuit) and performance metrics; Data link layer: error detection, Medium Access Control, Ethernet; Distance vector and link state routing; IPv4 - Fragmentation, CIDR Notation, Network Address Translation; TCP- flow control and congestion control, socket API; DNS and HTTP. | Trimmed. No longer listed: OSI and TCP/IP protocol stacks, framing, bridging, the separate shortest-path and flooding routing entries, IP addressing as a heading, ARP, DHCP, ICMP, UDP, SMTP, FTP and Email. Newly listed: performance metrics for switching. "Sockets" becomes "socket API". |
Digital Logic: the methods are now named
The 2026 text said "Boolean algebra. Combinational and sequential circuits. Minimization." The 2027 text says "Boolean algebra and minimization – algebraic technique, Karnaugh map, tabular method. Design of combinational and sequential circuits." Nothing that was examinable has disappeared. What changed is that the three minimisation methods are named, and the verb is now design.
The tabular method is usually taught as the Quine-McCluskey method; the syllabus does not use that name, so treat this as our reading. In practice it means you should be able to find prime implicants from a table, not only from a Karnaugh map, and to design a small combinational or sequential circuit from a specification rather than only analyse one. Number representation and fixed and floating point arithmetic stay, with "computer arithmetic" shortened to "arithmetic".
Computer Organization and Architecture: design, not just description
| 2026 | 2027 | Topic | Change |
|---|---|---|---|
| Machine instructions and addressing modes | Instruction set and addressing modes | Instructions | Reworded |
| ALU, data-path and control unit | Design of arithmetic and logic unit (ALU) | ALU | Design now named; data-path no longer named |
| Control unit (no detail) | Design of control unit – hardwired and microprogrammed | Control unit | Both control styles now named |
| Memory hierarchy: cache, main memory and secondary storage | Memory interfacing and hierarchy: performance, cache memory mapping | Memory | Interfacing, performance and cache mapping named; main memory and secondary storage no longer named |
| I/O interface (interrupt and DMA mode) | I/O interface (interrupt and DMA) | I/O | Reworded |
| Instruction pipelining, pipeline hazards | Instruction pipelining, pipeline hazards | Pipelining | Unchanged |
Cache questions were already the core of this section, and the 2027 wording makes cache mapping explicit. The new names to add to your notes are hardwired versus microprogrammed control units and memory interfacing. The dropped words matter less than they look: main memory is still part of "memory hierarchy", and the disk calculations that used to sit here appeared three times in the six 2024-2026 sets, so keep them in your practice while the question stays open.
Computer Networks: the biggest trim
| Topic in 2026 | In 2027 | Status (our reading) |
|---|---|---|
| Concept of layering: OSI and TCP/IP protocol stacks | Principles of Layering | Stacks no longer listed |
| Packet, circuit and virtual-circuit switching | Same, plus performance metrics | Performance metrics newly listed |
| Data link: framing, error detection, MAC, Ethernet bridging | Error detection, Medium Access Control, Ethernet | Framing and bridging no longer listed |
| Routing: shortest path, flooding, distance vector, link state | Distance vector and link state routing | Separate shortest-path and flooding entries no longer listed |
| Fragmentation and IP addressing, IPv4, CIDR, NAT | IPv4: fragmentation, CIDR notation, NAT | Kept; "IP addressing" no longer a separate item |
| IP support protocols: ARP, DHCP, ICMP | Not listed | No longer listed |
| Transport: flow and congestion control, UDP, TCP, sockets | TCP: flow control and congestion control, socket API | UDP no longer listed; sockets reworded |
| Application: DNS, SMTP, HTTP, FTP, Email | DNS and HTTP | SMTP, FTP and Email no longer listed |
Counting item by item, twelve named topics are no longer listed: the OSI and TCP/IP stacks, framing, bridging, shortest-path routing, flooding, ARP, DHCP, ICMP, UDP, SMTP, FTP and Email. That is our count, and "no longer listed" is deliberately cautious. Distance-vector routing still computes shortest paths, and a TCP question may still mention an IP address. What you should stop spending time on is standalone questions about those protocols.
Past questions that now fall outside the syllabus
| Question | Asked about | Marks |
|---|---|---|
| 2025 CS-1 Q16 | OSI layers matched to their functions | 1 |
| 2025 CS-2 Q16 | ARP (with a TCP statement that stays in scope) | 1 |
| 2025 CS-2 Q18 | ICMP, IGMP, OSPF and RIP in the IPv4 protocol field | 1 |
| 2026 CS-2 Q22 | Which of SMTP, FTP, DHCP and HTTP may broadcast | 1 |
Our reading of the six official 2024-2026 sets. By contrast, 2026 CS-2 Q43 on cyclic redundancy checks stays in scope under error detection, and IPv4 fragmentation questions such as 2025 CS-2 Q23 stay in scope even though that one packs a UDP segment.
For how the change affects the weight of each section, see GATE CS topic-wise weightage; for the papers themselves, GATE CS previous year papers with answer keys.
What to do with old notes, books and question banks
A practical rule for 2027 preparation
- Sections 1 and 4 to 9: any good 2026 material is still valid; the wording has not moved.
- Digital Logic: add the tabular method and practise designing circuits from a word description.
- COA: add hardwired versus microprogrammed control and memory interfacing; keep cache mapping at the centre; keep disk calculations until the organiser says otherwise.
- Computer Networks: drop standalone OSI-layer, ARP, DHCP, ICMP, UDP, SMTP and FTP questions from your revision list; keep TCP, IPv4 fragmentation, CIDR, NAT, routing algorithms, MAC, error detection, DNS and HTTP.
- Question banks and courses labelled "2027": check their networks chapter. If it still teaches the OSI model as a syllabus topic, it was not updated.
Our advice, based on our reading of the two official texts.
Also new: ME and RA as second papers
GATE lets a candidate write two papers from an approved list of combinations. For a candidate whose first paper is CS, the list has grown.
| Year | Second papers allowed with CS | Source |
|---|---|---|
| 2026 (IIT Guwahati) | DA, EC, GE, MA, PH, ST | GATE 2026 brochure, Table 4 |
| 2027 (IIT Madras) | DA, EC, GE, MA, ME, PH, RA, ST | GATE 2027 brochure, Table 4, and the two-paper combinations page |
The additions are Mechanical Engineering (ME) and Robotics and Automation (RA), a paper that is new in 2027; the organiser has posted a sample RA question paper on the download page. The brochure calls the combination list tentative. A second paper costs a second fee: per paper, 1,000 rupees at the regular rate for female, SC, ST and PwD candidates and 2,000 for others, rising to 1,500 and 2,500 in the extended period. Regular registration closes on 5 October 2026 and the extended period on 12 October 2026.
If you are weighing Data Science and AI against CS, see GATE DA vs GATE CS: which paper to write.
Practise it, don't just read it
The seven unchanged sections are where most of your marks will come from. Topic quizzes cover most of them.
The ProSyllabus GATE CS library currently has 29 topic quizzes of ten questions each, covering programming and data structures, algorithms, operating systems, databases, computer networks, compiler design and theory of computation, each with a worked explanation. There are no quizzes yet for Engineering Mathematics or Computer Organization, and Digital Logic has only number systems, so use the official papers for those. One networks quiz is built on the OSI and TCP/IP stacks, which the 2027 syllabus no longer lists.
Has the GATE CS syllabus changed for 2027?
Yes, in three of ten sections. Comparing the official 2026 and 2027 PDFs, Digital Logic, Computer Organization and Architecture, and Computer Networks were rewritten; the other seven sections are word for word the same. The comparison is our reading; the organiser has not published a change list.
Is DHCP in the GATE CS 2027 syllabus?
No. The 2026 syllabus listed ARP, DHCP and ICMP as IP support protocols; the 2027 Computer Networks section does not list any of them.
Is the OSI model in the GATE CS 2027 syllabus?
Not as a topic. The 2026 syllabus listed "OSI and TCP/IP Protocol Stacks"; the 2027 syllabus lists only "Principles of Layering".
Is disk scheduling removed from GATE CS 2027?
It is not clearly removed. "Secondary storage" is no longer named in Computer Organization, but the Operating System section still lists file systems and CPU and I/O scheduling. We would keep practising disk questions.
Which second papers can I take with GATE CS 2027?
DA, EC, GE, MA, ME, PH, RA and ST, according to the GATE 2027 brochure, which calls the list tentative. ME and RA are new compared with 2026.
More in this series
- GATE CS topic-wise weightage, counted from six official sets
- GATE CS previous year papers with official answer keys
- GATE CS qualifying marks, score vs rank, with calculator
- PSU recruitment through GATE CS 2027, from the notices
- GATE DA vs GATE CS: which paper to write
- GATE CS rank predictor
- GATE CS expected cut-off for top IITs
- GATE CS notice board: official updates
- GATE CS exam analysis
- GATE Computer Science complete guide
Sources
- official — GATE 2027 CS syllabus (IIT Madras)
- official — GATE 2026 CS syllabus (IIT Guwahati)
- official — GATE 2027 Information Brochure, IIT Madras, revised 27 Sep 2026
- official — GATE 2027 two-paper combinations
- official — GATE 2026 Information Brochure, IIT Guwahati (Table 4, two-paper combinations)
- official — GATE 2027 notifications
- official — GATE 2027 application fees
- official — GATE 2027 important dates
- official — GATE 2026 CS-1 question paper
- official — GATE 2026 CS-1 Answer Key
- official — GATE 2026 CS-2 question paper
- official — GATE 2026 CS-2 Answer Key
- official — GATE 2025 CS-1 question paper
- official — GATE 2025 CS-1 Answer Key
- official — GATE 2025 CS-2 question paper
- official — GATE 2025 CS-2 Answer Key
official = a document published by the conducting body. reported = a news or coaching site we could not check against an original. Where sources disagree this page says so rather than picking one.
