CPU Comparison
Intel Core i5-8400T vs Intel Core i7-5775C
A side-by-side comparison of specs, performance and value. The Intel Core i5-8400T is a low-power desktop processor belonging to the 8th generation Coffee Lake family. Released in April 2018, it is built on the 14nm process and features 6 cores and 6 threads. Unlike the standard i5-8400, the 'T' suffix denotes a reduced 35W TDP, making it ideal for small form factor (SFF) PCs and home theater setups. The base clock is set at 1.7 GHz, with a maximum turbo boost of 3.3 GHz. It includes 9 MB of Intel Smart Cache and supports dual-channel DDR4 memory up to 2666 MT/s. The integrated Intel UHD Graphics 630 handles basic display tasks. With 16 PCIe 3.0 lanes, it provides adequate expansion options. The i5-8400T is compatible with LGA 1151 sockets, though it requires 300-series chipsets for official support, offering a balance of efficiency and multi-core capability.
The Bottom Line
Overview & Launch
Specifications Compared
Performance Compared
Productivity
6 cores handle office tasks easily, though single-core is slower.
4 cores handle office tasks effortlessly, but lack modern IPC.
Gaming
Can handle light gaming, but low clocks limit high-refresh gaming.
The eDRAM provides incredibly smooth frame times in older games.
Virtualization
Good for 1-2 VMs, but lacks hyper-threading.
Capable of light VMs, but limited by 65W TDP.
Efficiency
Outstanding efficiency with a 35W TDP.
14nm process makes it incredibly power-efficient.
Specialized Performance
AI / ML
- No dedicated AI hardware.
- Low clocks make inference slow.
- No AI hardware
- eDRAM helps slightly with CPU inference
Content Creation
Gaming
- Low base clock can cause stuttering in CPU-bound games.
- UHD 630 is only good for very light titles.
- Best paired with a low-end discrete GPU if gaming.
- eDRAM reduces stutter in CPU-bound games
- Iris Pro 6200 good for older games
- Can be paired with a discrete GPU for better performance
Industry Impact
Best CPU by Use Case
Target Audience
Strengths & Weaknesses
Pros
- Extremely low 35W TDP
- 6 cores for parallel tasks
- Runs very cool
- Good for small form factor builds
Cons
- Low base and boost clocks
- Locked multiplier
- No Hyper-Threading
- End-of-life platform
Pros
- 128 MB L4 eDRAM
- Iris Pro 6200 graphics
- Drop-in upgrade for LGA 1150
- Unlocked multiplier
Cons
- Only 4 cores
- Supports DDR3 only
- Expensive on the secondary market
- Older 14nm process
Competitors & Alternatives
Intel Core i5-8400T
- AMD Ryzen 5 2400GERival
Low Power Desktop
- Compare head-to-headIntel Core i5-8400Rival
Mainstream Desktop
- AMD Ryzen 5 2600ERival
Low Power Desktop
- Compare head-to-headIntel Core i5-7400TRival
Previous Gen Low Power
- AMD Ryzen 3 2200GERival
Budget Low Power
Slightly faster clocks, same TDP.
Compare head-to-head- AMD Ryzen 5 3400GEAlt
Better integrated graphics.
Much faster modern architecture.
Compare head-to-head- AMD Ryzen 5 5600GEAlt
Better efficiency and performance.
Slightly higher clocks if buying used.
Compare head-to-head
Intel Core i7-5775C
- Compare head-to-headIntel Core i7-4790KRival
Desktop Enthusiast
- Compare head-to-headIntel Core i7-6700Rival
Desktop
- Compare head-to-headIntel Core i5-5675CRival
Desktop
- AMD FX-8370Rival
Desktop
- Compare head-to-headIntel Core i7-4790Rival
Desktop
- AMD Ryzen 5 5600GAlt
Modern APU with vastly superior integrated graphics.
- Intel Core i5-12400FAlt
Modern alternative with much better CPU performance.
Our Verdict on Each
A highly efficient 6-core processor perfect for compact builds, though its low clock speeds limit performance compared to the standard 8400.
Best for: Building a quiet home server or retro gaming rig on a budget.
Read the full reviewA fantastic drop-in upgrade for LGA 1150 systems. The eDRAM gives it surprising legs in older games, though its CPU performance is outclassed by modern hardware.
Best for: Upgrading an older LGA 1150 system for smooth retro gaming.
Read the full reviewFrequently Asked Questions
Which is better, Intel Core i5-8400T or Intel Core i7-5775C?
Based on our editorial ratings, the Intel Core i7-5775C comes out ahead with a score of 8.5/10. That said, the best choice depends on your workload — check the spec and performance breakdown above for gaming, productivity and efficiency differences.
Which is faster for gaming, Intel Core i5-8400T or Intel Core i7-5775C?
For gaming, the Intel Core i7-5775C leads with a gaming performance score of 75/100 among Intel Core i5-8400T and Intel Core i7-5775C.
Which uses less power?
The Intel Core i5-8400T has the lowest rated TDP. Power draw across these chips: Intel Core i5-8400T (35 W), Intel Core i7-5775C (65 W).
Do Intel Core i5-8400T and Intel Core i7-5775C use the same socket?
No. They use different sockets (Intel Core i5-8400T: LGA 1151, Intel Core i7-5775C: Intel Socket 1150), so each needs a compatible motherboard.
Which has more cores?
The Intel Core i5-8400T has the most cores. Core counts: Intel Core i5-8400T (6 cores), Intel Core i7-5775C (4 cores).
Which is faster in multi-core benchmarks?
The Intel Core i5-8400T posts the highest multi-core benchmark score. Multi-core results: Intel Core i5-8400T (8,500), Intel Core i7-5775C (7,000). Benchmark figures are approximate and workload-dependent.