# NVMe Adapter Swap — Z840 Step-by-Step

Date: 2026-08-18 Goal: Replace £8.99 x1-traced NVMe adapter with JEYI x4 adapter in slot 80:00.0 Expected gain: 890 MB/s → ~3,500 MB/s (4× faster model loads) Downtime: ~10 minutes

## Pre-Shutdown (remote)

```bash # 1. Stop Ollama sudo systemctl stop ollama

# 2. Verify nothing on /models sudo lsof /models 2>/dev/null # should be empty

# 3. Unmount sudo umount /models

# 4. Confirm NVMe device still visible (don't detach yet) ls /dev/nvme0n1

# 5. POWER OFF (not reboot — you need to open the case) sudo poweroff ```

## Physical Swap (at the machine)

1. Open case — Z840 side panel release latch 2. Slot 00:02.0 (top x16 slot) — remove old NVMe + adapter 3. Transfer NVMe to JEYI x4 adapter (M.2 2280, secure with screw) 4. Slot 80:00.0 — install JEYI adapter (second CPU's x4 slot, middle area)

1. Wiki says 80:00.0 is x4 and empty — verify visually
2. If 80:00.0 isn't free, use 00:1c.4 (also x4, also empty)

5. Close case, power on

## Post-Boot (remote)

```bash # 1. Check NVMe detected sudo nvme list # Should show KIOXIA 931GB

# 2. Check PCIe link speed (should be x4 now!) sudo lspci -vvv -s $(lspci | grep NVMe | awk '{print $1}') | grep LnkSta # Expect: Speed 8GT/s, Width x4

# 3. Mount (UUID unchanged — same NVMe, new adapter) sudo mount /models # Or: sudo mount UUID=91d71314-2c10-4580-ae63-3e06d886205a

# 4. Verify data intact ls /models/ollama/manifests/

# 5. Start Ollama sudo systemctl start ollama

# 6. Verify models load ollama list ollama run qwopus-mccoder –verbose “hello” 2>&1 | head -5

# 7. Benchmark (optional) dd if=/models/ollama/blobs/sha256-262843d4806aeb402336980badd414a72576b20b1e5d537647da15f16c4a4df of=/dev/null bs=1M count=1000 # Should show ~3.0-3.5 GB/s ```

## Key Details

## After Swap — P40 Plan

Slot 00:02.0 is now free for P40 #1 (one of three x16 slots). Full P40 plan: 00:02.0 + 00:03.0 + 80:02.0 → 3× Tesla P40 (72GB Vulkan). 3060s → Z600.