Instance Specification

This page describes the instance families, sizing options, and underlying hardware available for Zenlayer Elastic Compute (ZEC) instances. Use it to choose the right instance shape for your workload and understand the CPU and GPU hardware behind each family.

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1. Instance Families

ZEC instance families at a glance

ZEC offers six instance families, split by CPU vendor and by whether they back standard compute or GPU-attached instances:

Family	Role	CPU Platform	CPU Model(s)
z2a	Standard CPU	AMD EPYC 2nd Gen (Rome)	EPYC 7H12
z4a	Standard CPU	AMD EPYC 4th Gen (Genoa)	EPYC 9654
za4h	Standard CPU	AMD EPYC 4th Gen (Genoa)	EPYC 9554
z2i	Standard CPU	Intel Xeon Scalable 2nd Gen (Cascade Lake)	Xeon Gold 6254 · Xeon Gold 6248
z3a	GPU instance	AMD EPYC 3rd Gen (Milan)	EPYC 7543
z4i	GPU instance	Intel Xeon Scalable 4th Gen (Sapphire Rapids)	Xeon Gold 6430

GPU instance families (z3a, z4i) are deployed exclusively in GPU-enabled instances and are not available as standard compute.

za4h is currently available only in the ZEC Mumbai region.

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2. vCPU-to-RAM Ratios

Each family supports three ratio types so you can match your workload's memory profile:

Ratio Type	vCPU:RAM	Best For
CPU Intensive	1:2	Compute-bound workloads — batch processing, encoding, simulation
Standard	1:4	General-purpose workloads — web servers, application servers, APIs
Memory Intensive	1:8	Memory-bound workloads — caches, in-memory databases, analytics

Instance sizes scale from 1 vCPU up to 64 vCPU within each ratio type. For example, a z2a.std.16 is a 2nd-gen AMD instance with the 1:4 standard ratio and 16 vCPUs (16 vCPU / 64 GiB RAM).

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3. vNIC and Networking Limits

vNIC capacity scales with instance size. The following limits apply across all instance families:

vCPU Count	Max vNICs	vNIC Multi-Queue	Private IPv4 per vNIC
1–2	2	1	6–10
4–8	2	2–4	15
16	4	8	30
32	8	16	30
64	16	32	30

• vNICs: Maximum number of virtual network interfaces (including the primary vNIC) you can attach to an instance.

• vNIC Multi-Queue: Number of transmit (Tx) and receive (Rx) queues per vNIC. Higher counts improve network throughput and reduce latency.

• Private IPv4 per vNIC: Maximum private IPv4 addresses that can be assigned to a single vNIC.

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4. Regional Availability

Available instance sizes vary by location depending on inventory. Check the Zenlayer console when creating an instance to see what's available in your target region.

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5. CPU Specifications

5.1 z2a — AMD EPYC 2nd Gen (Rome)

AMD EPYC 7H12

Property	Value
Generation	AMD EPYC 2nd Gen (Rome)
Microarchitecture	Zen 2
Socket	SP3
Cores / Threads	64 / 128
Base Clock	2.60 GHz
Max Boost Clock	3.30 GHz
L2 Cache	32 MB (512 KB × 64)
L3 Cache	256 MB
Memory Controller	8-channel DDR4
Max Memory Speed	DDR4-3200
Max Memory Capacity	2 TB (4 TB with 3DS RDIMMs)
PCIe Version	PCIe 4.0
PCIe Lanes	128 per socket
TDP	280 W
Process Node	TSMC 7 nm (N7)

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5.2 z3a — AMD EPYC 3rd Gen (Milan)

AMD EPYC 7543 (GPU instances only)

Property	Value
Generation	AMD EPYC 3rd Gen (Milan)
Microarchitecture	Zen 3
Socket	SP3
Cores / Threads	32 / 64
Base Clock	2.80 GHz
Max Boost Clock	3.70 GHz
L2 Cache	16 MB (512 KB × 32)
L3 Cache	128 MB
Memory Controller	8-channel DDR4
Max Memory Speed	DDR4-3200
Max Memory Capacity	2 TB (4 TB with 3DS RDIMMs)
PCIe Version	PCIe 4.0
PCIe Lanes	128 per socket
TDP	225 W
Process Node	TSMC 7 nm (N7P)

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5.3 z4a — AMD EPYC 4th Gen (Genoa)

AMD EPYC 9654

Property	Value
Generation	AMD EPYC 4th Gen (Genoa)
Microarchitecture	Zen 4
Socket	SP5
Cores / Threads	96 / 192
Base Clock	2.40 GHz
Max Boost Clock	3.70 GHz
L2 Cache	96 MB (1 MB × 96)
L3 Cache	384 MB
Memory Controller	12-channel DDR5
Max Memory Speed	DDR5-4800
Max Memory Capacity	6 TB
PCIe Version	PCIe 5.0
PCIe Lanes	128 per socket
TDP	360 W
Process Node	TSMC 5 nm (N5)

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5.4 za4h — AMD EPYC 4th Gen (Genoa)

AMD EPYC 9554 (ZEC Mumbai only)

Property	Value
Generation	AMD EPYC 4th Gen (Genoa)
Microarchitecture	Zen 4
Socket	SP5
Cores / Threads	64 / 128
Base Clock	3.10 GHz
Max Boost Clock	3.75 GHz
L2 Cache	64 MB (1 MB × 64)
L3 Cache	256 MB
Memory Controller	12-channel DDR5
Max Memory Speed	DDR5-4800
Max Memory Capacity	6 TB
PCIe Version	PCIe 5.0
PCIe Lanes	128 per socket
TDP	360 W
Process Node	TSMC 5 nm (N5)

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5.5 z2i — Intel Xeon Scalable 2nd Gen (Cascade Lake)

Intel Xeon Gold 6254

Property	Value
Generation	2nd Gen Intel Xeon Scalable (Cascade Lake)
Microarchitecture	Cascade Lake
Socket	LGA 3647 (P0)
Cores / Threads	18 / 36
Base Clock	3.10 GHz
Max Turbo Frequency	4.00 GHz
L2 Cache	18 MB
L3 Cache (LLC)	24.75 MB
Memory Controller	6-channel DDR4
Max Memory Speed	DDR4-2933
Max Memory Capacity	1 TB per socket
PCIe Version	PCIe 3.0
PCIe Lanes	48 per socket
TDP	200 W
Process Node	Intel 14 nm++

Intel Xeon Gold 6248

Property	Value
Generation	2nd Gen Intel Xeon Scalable (Cascade Lake)
Microarchitecture	Cascade Lake
Socket	LGA 3647 (P0)
Cores / Threads	20 / 40
Base Clock	2.50 GHz
Max Turbo Frequency	3.90 GHz
L2 Cache	20 MB
L3 Cache (LLC)	27.50 MB
Memory Controller	6-channel DDR4
Max Memory Speed	DDR4-2933
Max Memory Capacity	1 TB per socket
PCIe Version	PCIe 3.0
PCIe Lanes	48 per socket
TDP	150 W
Process Node	Intel 14 nm++

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5.6 z4i — Intel Xeon Scalable 4th Gen (Sapphire Rapids)

Intel Xeon Gold 6430 (GPU instances only)

Property	Value
Generation	4th Gen Intel Xeon Scalable (Sapphire Rapids)
Microarchitecture	Sapphire Rapids
Socket	LGA 4677
Cores / Threads	32 / 64
Base Clock	2.10 GHz
Max Turbo Frequency	3.40 GHz
L2 Cache	40 MB
L3 Cache (LLC)	60 MB
Memory Controller	8-channel DDR5
Max Memory Speed	DDR5-4800
Max Memory Capacity	4 TB per socket
PCIe Version	PCIe 5.0
PCIe Lanes	80 per socket
TDP	270 W
Process Node	Intel 7 (10 nm ESF)

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6. GPU Specifications

NVIDIA GeForce RTX 4090

Property	Value
Architecture	Ada Lovelace
GPU Die	AD102
CUDA Cores	16,384
Tensor Cores	512 (4th Gen)
RT Cores	128 (3rd Gen)
GPU Memory	24 GB GDDR6X
Memory Bus Width	384-bit
Memory Bandwidth	1,008 GB/s
Memory Speed	21 Gbps
L2 Cache	72 MB
FP32 Performance	82.6 TFLOPS
FP16 Performance	165.2 TFLOPS (non-sparse)
TF32 Tensor Performance	82.6 TFLOPS (non-sparse) / 330.3 TFLOPS (sparse)
Boost Clock	2,520 MHz
Interface	PCIe 4.0 x16
TDP	450 W
Process Node	TSMC 4 nm (N4)
Launch Date	October 2022

NVIDIA Tesla T4

Property	Value
Architecture	Turing
GPU Die	TU104
CUDA Cores	2,560
Tensor Cores	320 (2nd Gen)
GPU Memory	16 GB GDDR6
Memory Bandwidth	320 GB/s
FP32 Performance	8.1 TFLOPS
FP16 Performance	65 TFLOPS (with sparsity)
INT8 Performance	130 TOPS
INT4 Performance	260 TOPS
ECC	Supported
Interface	PCIe 3.0 x16
Form Factor	Low-profile, single-slot
TDP	70 W
Process Node	TSMC 12 nm
Launch Date	September 2018