🎯 Final Verdict: Which to Choose?
The PNY CS900 is objectively superior to the Kingston A400 in sustained write performance (14% more) and has better optimization of the Phison S11 controller. Both are excellent budget options, but the CS900 offers better value.
At Omar YT Play we reviewed How to Install PNY CS900 SSD.
🔍 Introduction: Two Budget Legends
The PNY CS900 and Kingston A400 are two of the best-selling SATA SSDs in the budget segment. Both use the same Phison S11 controller and are DRAM-less, but differ in optimization and performance. We'll analyze all technical aspects to determine which is better.
As seen at Omar YT Play in PNY CS900 1TB SSD Review.
📋 Complete Technical Specifications
| Specification | PNY CS900 | Kingston A400 |
|---|---|---|
| Controller | Phison S11 | Phison S11 |
| NAND Flash | 3D TLC NAND | 3D TLC NAND |
| DRAM Cache | None (DRAM-less) | None (DRAM-less) |
| Sequential Read | 535 MB/s | 500 MB/s |
| Sequential Write | 515 MB/s | 450 MB/s |
| 4K Random Read | 90,000 IOPS | 80,000 IOPS |
| 4K Random Write | 80,000 IOPS | 70,000 IOPS |
| TBW (120GB) | 80 TB | 70 TB |
| MTBF | 1.5 million hours | 1.5 million hours |
| Warranty | 3 Years | 3 Years |
| Form Factor | 2.5" 7mm | 2.5" 7mm |
⚙️ Phison S11 Controller: What You Need to Know
Phison S11 Features
- 8-channel architecture
- Supports 3D TLC NAND
- DRAM-less design
- LDPC ECC engine
- Native SATA 6Gb/s
- SLC caching technology
DRAM-less Limitations
- No external DRAM cache
- Uses HMB (Host Memory Buffer)
- Lower performance in heavy workloads
- GC (Garbage Collection) impacts
- Write amplification issues
- Not for server use
Both SSDs use the same Phison S11 controller, which is why their performance is so similar. The differences come from firmware optimization and NAND quality selection by each manufacturer.
📊 Real-World Performance Benchmarks
These tests were performed on identical systems (Intel i5-8400, 8GB DDR4, Windows 11) with both SSDs in the same slot to ensure fair comparison.
We recommend checking at Omar YT Play: Gaming SSD Drives Comparisons | OMAR YT PLAY.
| Test | PNY CS900 120GB | Kingston A400 120GB | Difference |
|---|---|---|---|
| CrystalDiskMark Seq Read | 532 MB/s | 498 MB/s | +6.8% |
| CrystalDiskMark Seq Write | 512 MB/s | 448 MB/s | +14.3% |
| AS SSD 4K Read | 42.3 MB/s | 38.7 MB/s | +9.3% |
| AS SSD 4K Write | 152.4 MB/s | 133.8 MB/s | +13.9% |
| PCMark 10 Storage | 4,820 pts | 4,210 pts | +14.5% |
| Boot Time (Windows 11) | 12.3 sec | 13.1 sec | -0.8 sec |
| Game Load (Cyberpunk 2077) | 58.4 sec | 62.7 sec | -4.3 sec |
| File Transfer (10GB) | 21.2 sec | 24.8 sec | -3.6 sec |
The PNY CS900 consistently outperforms the Kingston A400 in all tests, with the most significant differences in sustained write operations (up to 14% more).
💻 Recommended Use Cases
Operating System Drive
Both SSDs are excellent for OS installation. The CS900 offers slightly faster boot times and application loading, but the difference is minimal for daily use.
Gaming Storage
For gaming, both provide a significant improvement over HDDs. The CS900 loads games ~7% faster, which is noticeable but not transformative.
Content Creation
For light content creation (photo editing, basic video), both are suitable. For heavy workloads, consider NVMe SSDs with DRAM cache.
Not Recommended For
- Server applications
- Heavy database workloads
- Continuous 24/7 operation
- Professional video editing
💰 Price/Performance Ratio
PNY CS900 - Better Value
- 14% more write performance
- Better firmware optimization
- Higher TBW rating
- Consistent performance
- Same price range
Kingston A400 - Budget Option
- Slightly cheaper in some retailers
- Well-known brand
- Same warranty period
- Adequate for basic use
- Widely available
The price difference between both models is usually negligible ($2-5 USD), making the PNY CS900 the clear winner in terms of value.
⚖️ Advantages and Disadvantages
PNY CS900 Advantages
- Higher sequential read/write speeds
- Better 4K random performance
- More optimized firmware
- Higher TBW rating (longer life)
- More consistent performance
PNY CS900 Disadvantages
- Slightly more expensive in some stores
- Less recognizable brand than Kingston
- Same DRAM-less limitations
Kingston A400 Advantages
- Very well-known brand
- Widely available globally
- Slightly cheaper in some retailers
- Same 3-year warranty
Kingston A400 Disadvantages
- 14% lower write performance
- Less optimized firmware
- Lower TBW rating
- Inconsistent performance
PNY CS900
For offering 14% more sustained write performance, better firmware optimization, and higher TBW rating at essentially the same price point.
Buy at the Best Price
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