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Block storage: EBS and ESSD

Capacity, IOPS, throughput, commitment, snapshots, and instance-channel limits for AWS EBS gp3 and Alibaba ESSD.
Important

Snapshot: 2026-08-22 · AWS us-east-1 · Alibaba Cloud cn-hangzhou · 1 USD = 6.7817 CNY. Exact rates vary by region. The comparison aligns provisioned capacity and requested IOPS/throughput, not latency or service level.

Direct answer

“Price per GB” is not a valid block-storage comparison by itself. It can rank gp3 as cheaper at baseline and then reverse the answer once performance is matched. A usable bill must price at least four things:

monthly block cost=capacity+IOPS+throughput+snapshots and recovery+network path \begin{aligned} \text{monthly block cost} ={}& \text{capacity} + \text{IOPS} + \text{throughput} \\ &+ \text{snapshots and recovery} + \text{network path} \end{aligned}

The final usable performance is also bounded by the instance:

usable I/O=min⁡(volume limit,instance storage-channel limit) \text{usable I/O} = \min(\text{volume limit}, \text{instance storage-channel limit})

Paying for IOPS that the attached instance cannot deliver creates cost without performance.

Two pricing philosophies

AWS EBS gp3: capacity and performance are explicit meters

The snapshot uses:

  • Capacity: $0.08/GB-month (¥0.5425).
  • Included: 3,000 IOPS and 125 MiB/s.
  • Extra IOPS: $0.005/IOPS-month.
  • Extra throughput: $0.04/MiB/s-month in the exact us-east-1 snapshot.

So:

Cgp3=0.08G+0.005max⁡(I−3000,0)+0.04max⁡(T−125,0) \begin{aligned} C_{gp3} ={}& 0.08G + 0.005\max(I-3000,0) \\ &+ 0.04\max(T-125,0) \end{aligned}

All three are provisioned meters. Actual low usage does not refund unused provisioned IOPS or throughput.

Alibaba ESSD: capacity often carries a performance curve

Traditional PL0–PL3 bind capacity to a product level. AutoPL separates capacity from optional provisioned and burst performance, but capacity still includes a rising baseline:

Ibase=max⁡(min⁡(1800+50G,50000),3000) I_{base}=\max(\min(1800 + 50G, 50000), 3000) Tbase=max⁡(min⁡(120+0.5G,350),125) T_{base}=\max(\min(120 + 0.5G, 350), 125)

At 200 GiB this yields 11,800 IOPS and 220 MB/s; at 2,048 GiB the baseline reaches 50,000 IOPS and 350 MB/s. Alibaba’s documentation also notes that the attached instance can impose the lower I/O ceiling.

Capacity meter alone

Product Capacity price Included/baseline performance PAYG-equivalent 1 year 3 years 5 years
EBS gp3 ¥0.5425/GiB-month 3K IOPS, 125 MiB/s same list meter contract-specific contract-specific contract-specific
ESSD PL0 ¥0.50/GiB-month capacity-coupled ¥0.7665 ¥0.425 ¥0.25 ¥0.25
ESSD PL1 / AutoPL ¥1.00/GiB-month capacity-coupled to 50K / 350 ¥1.533 ¥0.85 ¥0.50 ¥0.50
ESSD PL2 ¥2.00/GiB-month higher level; minimum 461 GiB ¥3.066 ¥1.70 ¥1.00 ¥1.00
ESSD PL3 ¥4.00/GiB-month higher level; minimum 1,261 GiB ¥6.132 ¥3.40 ¥2.00 ¥2.00

At this layer, gp3 is near PL0 and about 54% of PL1/AutoPL. That statement is true but incomplete.

Performance-matched scenarios

Capacity and target EBS gp3 ESSD AutoPL baseline gp3 / AutoPL Reading
200 GiB · 3K IOPS · 125 MiB/s ¥108.51/month ¥200.00/month 0.54× gp3 baseline is cheaper
200 GiB · 11.8K IOPS · 220 MiB/s ¥432.67/month ¥200.00/month 2.16× AutoPL capacity baseline is cheaper
2,048 GiB · 50K IOPS · 350 MiB/s ¥2,765.85/month ¥2,048.00/month 1.35× AutoPL remains cheaper at its baseline ceiling

This is the core block-storage insight: the answer flips because one product charges extra performance separately while the other bundles a capacity-driven baseline. It does not prove equal latency, durability, burst behavior, or instance delivery.

The exact rows are in block_storage_scenarios.csv.

What the price table still hides

Snapshots and recovery

EBS snapshots bill changed blocks in S3-backed storage; cross-region copy, archive retrieval, fast snapshot restore, time-bounded copy, and provisioned initialization can add separate meters. ESSD snapshots, backup products, and cross-region recovery have their own lifecycle and transfer costs. A recovery budget needs restore time and restore throughput, not just snapshot GB-month.

Topology and network

A single cloud disk is an availability-zone resource. Cross-AZ database or application topologies may duplicate volumes and add network charges. Managed database storage can price capacity, IOPS, and throughput at different markup factors from raw block storage.

Provisioned versus consumed

Both capacity and performance can be paid before they are used. Track:

  • provisioned vs used GiB;
  • provisioned vs observed P95/P99 IOPS;
  • provisioned vs observed throughput;
  • instance channel utilization;
  • snapshot growth and orphan retention;
  • commitment coverage and unused term value.

Extreme-performance layers

At the high end, capacity is no longer the dominant meter. AWS io2 prices provisioned IOPS by volume-level tiers. Alibaba ESSD PL-X similarly separates capacity and IOPS; an official example for 2,048 GiB and two million IOPS totals ¥152,048/month, of which ¥150,000 is performance. Low-end disks monetize capacity; high-end disks monetize performance.

Historical insight

AWS gp2 to gp3 reduced capacity price only 20%, from $0.10 to $0.08/GB-month. For a 200 GiB volume, however, included baseline IOPS rose from 600 to 3,000, cutting price per baseline IOPS by 84%. Alibaba’s 2016 SSD and 2026 ESSD PL1 both anchor at ¥1/GB-month; performance, reliability, and product semantics improved while the capacity meter stayed flat.

This is why “storage prices did not fall” and “storage price-performance improved sharply” can both be true. See Cloud price history.

A minimum bill worksheet

Before comparing disks, fill one row per volume:

Field Required value
Region / AZ Exact deployment path
Provisioned and used capacity GiB, both values
IOPS baseline, provisioned, P95/P99 observed
Throughput baseline, provisioned, P95/P99 observed
Latency requirement P50/P99 and block size
Instance channel max IOPS and throughput
Snapshot and restore changed GB, retention, RTO, copy path
Topology number of volumes, replicas, AZs
Term PAYG, monthly, 1/3/5 year, residual commitment

If any of these is missing, a capacity-price ratio is a lead, not a conclusion.

Boundaries

  • GB and GiB are retained exactly as providers publish them.
  • AutoPL baseline does not imply the attached instance can deliver it.
  • This comparison does not equalize latency, durability, burst, or SLA.
  • AWS rates are regional and tax-exclusive; Alibaba China-site rates are tax-inclusive.
  • Prices may have changed after 2026-08-22; refresh before purchase.

Data and sources